Until today, the round temple of Tivoli is considered as the ideal of Romanticism for artists and architects. It was modeled in various interpretations by the grand masters of “phelloplastics” and carried across the Alps. Today Dieter and Malgorzata not only restore the few preserved objects, but they also create new cork models of the temple for various requirements. With this they not only keep a forgotten craftsmanship alive, but also try to redirect the viewer’s gaze to perfect proportions and beauty …


04_20200805_184031Next to it Dieter builds another cork model of an antique aeroduct. The first visualization is created in collaboration with Florian Dombois…


The ancient Romans are known for their viaducts, pathways, and aqueducts, watercourses, with which they directed and shaped spring water over many kilometres and led it into their cities. Similarly, aeroducts direct and shape the wind, while at the same time guiding it in a circle to study its behaviour. In aeroducts, phenomena such as thought resistance or torsional wind can be simulated and understood in order to, for example, optimise ventilation or underfloor heating in houses. The research facility is also suitable for extended contexts when, in urbanism (cf. Vitruvius‘ „10 Books of Architecture“), attempts are made to improve the human climate by intelligently setting building volumes and creating spaces in between. Today these facilities are called wind tunnels.

In the attached photos, an excavation site of such an aeroduct is reconstructed according to drawings by the artist Florian Dombois. Dombois himself runs a wind tunnel laboratory on the roof of the Zurich University of the Arts  AERODUCT  and realized, among other things, a wind tunnel for the Research Pavilion in Venice from found building materials from the lagoon. For the Day of the Monument in September 2020, he will realize an aeroduct as a 1:1 model made of mudbricks in Allschwil, Switzerland, together with Martin Burr and the Fachwerk Association.



Making a column requires a lot of calculations and accurate work. The right representation of the ENTASIS gives the object the correct proportion. After determining the exact shape, Dieter grinds it by hand on an ordinary lathe …


In the 18th century, a cork model of the Castor and Pollux temple in Rome was a popular sovenir for travelers of the „Grand Tour“
Today Dieter and Malgorzata create a new interpretation of this ruin scale 1:50.                   Let’s look over their shoulder at work …

Diter Cöllen Korkmodell Tempel der Dioskuren

It all starts with a solid foundation


The Pont du Gard is founded on solid rock. To visualize this perfectly in the model Dieter uses 9 years grown cork bark from selected oaks in Portugal. After gluing the cork 02_20200203_10473101_20200203_105254he will treat the material like a sculpture to imitate the beauty of nature as best as possible…


With every new project Dieter is supported by many people in the background. First there are the cork workers in Portugal, who provide him with the best material. In Germany, he can rely on Mr. Engels for the woodwork with his knowledge and experience. Dieter himself fell in love with cork in 1962 – until today …KorkernteDieter Cöllen, Herr EngelsMy beautiful picture


As always when a project after a long time of working comes to its end we feel pleasure and sadness at the same time. Now that the Colosseum is finished its time to open the view to further projects.

Lets wait for while and see

what Dieter is planing next…


Today Dieter shows us for the last time the inner construction of the Colosseum. After that he will fix it on the wooden base to prepare the object for the final photo shooting. Meanwhile Malgorzata glues the last cork block where it belongs


Yesterday Dieter had charming guests from Finland. The famous TV moderator ELLA KANNINEN  and her team visited his “small kitchen” to talk about cork models and filmed Dieter at work.

We all are waiting now for the result that will be shown at the beginning of next year – thank you so much…





Now the upper section of the facade is nearly finished including the brackets which support the wooden poles for the shading construction. We don’t know much about that, because all that disappeared during the centuries. Watch here a video about an idea how the VELARIUM could have worked.




Imagine yourself – sitting there on a Sunday morning in company with some friends having this spectacular view of the Colosseum. Some birds are singing in the trees interrupted by the roaring noise of more than 50 000 people hypnotized by a bloody fight behind that beautiful facade…




Since Luigi Carotti built the last cork model of the Colosseum in 1840 nobody toughed that theme again. Today Dieter Cöllen decided to create another object of this incredible monument. He calls his project “Homage á Luigi Carotti” and wants to discover if his artwork can exist beside the quality of the ancient master. The audience is invited to decide…

After getting the plans Dieter starts first to form the oval walls of the Colosseum. Here you can see him working on that basic part. With the assistance of Malgorzata he builds the support structures…



in the 18th century most of the cork models where manufactured in a hurry due to high demand. Especially the wooden base was often made very carelessly. For that reason many old cork models are in very bad condition today. For Dieter, a solid base is therefore the top priority. After this work is done he begins to restore the cork frame of the object…


Dieter´s next restoring project is an ancient cork model of the pyramid of Cestius / Rome. Probably it was manufactured in the studio of Carl May. This object was once a well loved “Souvenir” of the Grand Tour. This model went through several hands and was badly treated during the centuries.


Another new challenge for Dieter…


After its long journey across the ocean the Colosseum safely reached San Francisco. There in a famous private collection it is now the centerpiece of the exhibit surrounded by other models of the 19th century.


Restoration work is done and the Colosseum was packed and left Dieter´s studio to cross the ocean and all the way through the States to San Francisco / California. A four month project that helps a ruin surviving the next 300 years…


Back from the Provence Dieter uses the natural pigments he got to set warm “late afternoon sunlight” on the surface of the Colosseum. This very important part of the work appeals to our emotions and is the final tough of every restoration…Colosseum


To finish his work Dieter follows the footsteps of the old masters. They only used natural pigments to colour their objects. No chemical reaction destroys the surface of the cork and the smooth expression of the sculptures survive for centuries. To get the pigments Dieter visits one of his most favourite spots in the Provence – the small village Roussillon. Here he takes a bath in colours inspired by nature…





Roussiloncöllen 17.08.2015 012cöllen 17.08.2015 001cöllen 17.08.2015 013cöllen 17.08.2015 025


work on the Colosseum reaches a significant stage. The monument has to be “married” with its base. 150 points must be glued at the same time connected with 13 wooden dowels.

This demanding action can not be done by one alone. Dieter has support from his friends Stefan and Gerd. Together they achieve a perfect result. This effort has the purpose of creating an unbreakable connection that will last for the next 300 years…P1430982P1430984P1440013P1440031P1440040P1440047P1440069P1440093P1440160P1440179


Now the upper section of the facade is nearly finished including the brackets which support the wooden poles for the shading construction. We don’t know much about that, because all that disappeared during the centuries. Watch here a video about an idea how the VELARIUM could have worked.


After the capitals where dipped in different liquids, the elements are glued on the facade. Now the proportions are visible again as well as the order of the columns…

Ca 1 (2)Ca 1 (3)


After the drying process of the silicon Dieter prepares the “filling” according to an old recipe. The main ingredient is powdered clay but also other components are necessary to get the best result.

The most important is to get the bubbles out of the liquid. After the drying every single piece must be taken out of the mold carefully. In further steps they must be cleaned with a rotating brush and later coloured with natural pigments…




…at the Lindenau – Museum by Victoria Kubale

The Lindenau Museum in Altenburg, named after the 19th century statesman, astronomer and art collector Bernhard August von Lindenau (1779-1854), houses a vast collection of paintings from the 13th century to the present, graphic works, sculpture, a historical library, antiquities, plaster casts and miniature models of ancient architecture.

Lindenau, who was acquainted with Johann Wolfgang von Goethe and Alexander von Humboldt, founded the museum after traveling Italy and France where he purchased a considerable number of artworks. In order to present the objects in an appropriate way he initiated the construction of a new building at his residence in Altenburg, the “Pohlhof”. The museum opened its doors on april 1st in 1848.

Until 1854, the year of his death, Lindenau extended his collections with further purchases. Eventually, the rooms of the building at the Pohlhof became too confined, so that a new one was built in 1874 at the behest of the duchy of Saxe-Altenburg on the edge of the park of the residence castle Altenburg. The building represents a certain architectural type of Pinacotheca or “Gemäldegalerie”, which was created by Leo von Klenze with the Alte Pinakothek in Munich.

In the 20th and 21th century the museum laid a focus on the acquisition of modern and contemporary art, especially graphic works. Today it houses the most comprehensive collection of works of Gerhard Altenbourg (1926-1989) worldwide.

However, the collections of Lindenau, which focused on Ancient Greece and the early Italian Renaissance, still remain the heart of the museum. They comprise 180 Italian panel paintings (of Sandro Botticelli, Fra Angelico, Massaccio, Luca Signorelli, Pietro Perugino and Guido da Siena), about 400 Greek and Etruscan vases, 150 plaster casts of ancient Greek to neoclassical sculpture as well as an art library and models of ancient architecture made of cork, bronze and terracotta.

Modeling small replicas of historical buildings of cork (phelloplasty) has its origins in the late 16th century nativity scene sculpture. It evolved into an independent (art) genre and became a common handicraft in Italy in the 18th century, when more and more erudite travelers and affluent Europeans with an interest in classical antiquity visited Rome and increased the demand for antiquities and souvenirs. The selection of displayed architecture comprised several temples, theaters, triumphal archs, sepulchral and infrastructural architecture and met the taste of this clientele. Because of its porous look, its color and easy processing cork was an ideal material to represent the reverent but fading splendor of ancient architecture.
But Lindenau was not looking for a nice souvenir. He intended to use the models as a substitute for studies in situ to “offer a visualization of the ancient Greek and Roman art of construction”1, thus for a pedagogical purpose. During his stay in Italy in 1843 he socialized with Emil Braun, classical archaeologist and secretary to the German Archaeological Institute in Rome. Between 1845 and 1850 Braun ordered cork replicas from the Roman modeler Luigi Carotti (Works et models of Cork, Rome, No. 13. Via del Boschetto 2. Floor) for Lindenau.

The Carotti models consist of the Colosseum (amphitheatrum flavium), the Temple of Mars Ultor and three Greek temples in Paestum: the archaic first Temple of Hera (also called “the Basilica”), the second Temple of Hera (so-called Temple of Poseidon), which dates back to 450 BC, and the late archaic Temple of Athena. Besides, the museum’s model of the Temple of Antoninus Pius and Faustina, which is a permanent loan to the residence castle Altenburg, was probably also crafted by Carotti. All of them are in an intact condition.

The model of the Colosseum was commissioned in 1845 by Emil Braun to Luigi Carotti. The agreed price was 50 Scudi. But shortly after Carotti started work, a shortage of cork occurred, so that the completion of the model was delayed. Braun did not only manage to procure the urgently required material in 1847, but also to convince Carotti to complete the protracted and tedious work on the model after he intended to reject the order.2 The small-scale Colosseum finally arrived in 1850 at the Pohlhof.

The model has a height of 32.5 cm, a longitudinal axis of 100 cm and a transverse axis of 72 cm. Hence, it displays the Colosseum in a scale of 1 to 185, but the proportions of the original, which is less elongated, were not fully observed. The interior features two tiers of the same size. Apart from that, Carotti refrained a reconstruction of the interior space. Nevertheless, the model captivates the beholder with its detailed design of the architectural decoration such as the half-columns of the Tuscan, Ionic and Corinthian orders on the outer facade. Thanks to the restoration by Dieter Cöllen in 2017, the model is in a good condition today.

Besides the models of Carotti the Lindenau Museum owns five cork miniatures of the first German cork carver Carl May (1747-1822), which were crafted in Erfurt or Aschaffenburg around 1800. These include the Pyramid of Cestius, the Grotto of Egeria, the Porticus Octaviae, the “Temple of the Cough” (Tempio della Tosse) and the Temple of Minerva Medica.
In Naples Emil Braun purchased two Sicilian temples from an unknown modeler for Lindenau: the temple in Segesta and the so-called Temple of Concordia in Agrigento. In addition, there are three more models in the museum which Braun acquired in Rome. These are the Basilica of Maxentius and Constantine, the Pantheon and the Arch of Drusus made of tuff.

Except for Luigi Carotti and Carl May three other Italian small-scale architects have to be mentioned: the famous Antonio Chichi (1743-1816), who also crafted a model of the amphitheatrum flavium (now in the Wilhelmshöhe Palace in Kassel), Augusto Rosa (1738-1784) and Giovanni Altieri (attested 1767-1790). They beared the job title “architetto”, which indicates that they were conversant with the art of construction in general. As a source of inspiration they used large-scale views of ancient architecture of the engraver Giovanni Battista Piranesi.3

The Lindenau Museum houses also a collection of bronze models. Their provenance is not conclusively clarified yet, but there were certainly crafted in 19th century Italy. They represent the so-called Temple of Vesta, the Temple of Saturn, the Temple of Vespasian and Titus, the Columns of Phocas, Trajan and Marcus Aurelius, the equestrian statue of Marcus Aurelius as well as two different sized models of the Lateran Obelisk and three further Roman columns made of decorative stone.

The Temple of Castor and Pollux, which is made of terracotta, was produced in the Thonwaaren-Fabrik Franz Naumann in the second half of the 19th century. The Choragic Monument of Lysicrates and other architectural elements like a part of the second Temple of Hera in Paestum were also made by this manufacturer. Under the direction of Dr. Martin Boss archaeology students of the University of Erlangen restored the terracotta models in the early 2000s.

Today, the cork model of the Colosseum is one of the most frequently lent art work of the Lindenau Museum. It went on a journey from Altenburg to Erlangen (“Nur ein Souvenir?”, Stadtmuseum Erlangen, 1997), Munich (Internationale Handwerksmesse 2003, “Architektur+Sport. Vom antiken Stadion zur modernen Arena”, Entrepreneurial University, 2006), Würzburg (“Freunde, ich habe einen Tag verloren. Rom zur Zeit des Kaisers Titus”, Martin von Wagner-Museum of the University of Würzburg, 2007), Basel (“Von Harmonie und Maß”, Skulpturenhalle, 2009), Saarbrücken (“Grand Tour. Reisen zu antiken Stätten”, Museum für Vor- und Frühgeschichte and Saarlandmuseum – Alte Sammlung, 2017) and Fribourg, where it can be currently seen in the exhibition “ROMA! Gravures de la collection Clemens Krause” of the Musée d’Art et d’Histoire.

1 „[…] eine Anschauung der Bauweise der Griechen und Römer zu eröffnen, […].“ J. G. Quandt, H. W. Schulz, Beschreibung der im neuen Mittelgebäude des Pohlhofs befindlichen Kunst-Gegenstände, Altenburg 1848, p.87.
2 “Endlich ist auch das Colosseum in voller Arbeit. Ich habe viele Noth darum gehabt. Zuletzt wollte der Verfertiger nicht mehr Contract halten und die Arbeit ganz zurückweisen. Einige Scudi für den Kork habe ich zulegen müssen. Ich werde sie Ew. Exc. an etwas anderem zu ersparen suchen.“, excerpt from a letter from E. Braun to B. v. Lindenau dated 11/30/1847.
3 S. Reim, Bernard August von Lindenaus Korkmodelle, in: Palmyra. Zerstörte Erinnerung, Altenburg 2017, 43-46, p. 44.


… by Prof. Dr. Valentin Kockel

Not much is known about the life of Luigi Carotti. Models from his workshop are documented for the period from 1830 to 1850. During this time, he worked out of premises in Via delle Vite, and – before or after this period – in Via del Boschetto, as we know from the English labels on his models. Both streets are situated near Piazza di Spagna, where foreign visitors tended to take their lodgings when in Rome.

So far we mainly know of models depicting the ruins of Rome, the usual highlights of every visit: the Arch of Constantine, Colosseum, Temple of Antoninus and Faustina, Temple of Castor and Pollux, Temple of Mars Ultor, Temple of Saturn and the Column of Phocas. Amongst these, the highly elaborate and therefore costly Colosseum stands out the most. Carotti was able to sell this model at least three times. Compared to the models of his predecessors, it represented the actual state of the monument, as it showed the restorations of 1807 und 1823. The choice of depicting the hardly spectacular late Antique Column of the Emperor Phocas on the Roman Forum was probably due to the interests of English travelers: the column was first excavated during the French occupation and a second time in 1817 by the Duchess of Devonshire. The overall increased interest in Greek Doric architecture that prevailed in the 19th century is attested to by models of the temples in Paestum and Sicily.

Initially, Carotti’s models were probably bought by private collectors, but later became part of the collections of learned societies (Edinburgh, St. Petersburg) or museums (Cambridge and Altenburg). The Lindenau-Museum in Altenburg (Thuringia) is the only institution to hold a larger number of models with eight specimen, amongst them a well-preserved Colosseum. Individual models have appeared on the art market, often heavily fragmented. One of these was the model of the Colosseum that is now held by the Piraneseum (San Francisco) and is being restored by Dieter Coellen.

Carotti’s work occurred at a time when interest in cork models was already on the decline. In Rome, he seems to have been the last of his profession whose oeuvre we can still follow at least fragmentarily. Compared to the works of Chichi and Lucangeli (Rome), Padiglione (Naples) or Georg May (Germany) his models appear somewhat dry. Apart from using massive cork as primary building material, Carotti utilized reddish, fired terracotta elements for ornamental details, such as friezes and capitals of the Corinthian order. Their colour has often faded away, but would originally have produced a strangely spotted effect.




On the facade of the Colosseum we find Doric, Ionic and Corinthian columns. Carotti modeled them very accurately in this small scale. But most of them are lost ore crumbled to dust. To make the original beauty visible again, Dieter first produces silicon moulds of the best pieces….

After the drying process he will be able to pour the negative in further stepps…


Imagine yourself – sitting there on a Sunday morning in company with some friends having this spectacular view of the Colosseum. Some birds are singing in the trees interrupted by the roaring noise of more than 50 000 people hypnotized by a bloody fight behind that beautiful facade…




For many years Carottis Colosseum was destroyed and nothing more than a ruined ruin. Now for the first time the outer wall is rebuilt. There is still a lot of restoring work to do but we can already imagine the beauty of this monument. A beauty that is deceptive, because this wall hid one of the most bloodiest spots in the world…





Most of the pillars of the outer wall are lost, broken or not in an upright position. Each of them needs to be restored or rebuilt. A constructed “horizon” helps Dieter with the assembly…



Here we see the big “Sperone di Pio VII” constructed by Giovanni Stern in 1807 under Pope Pius in order to stabilize the outer wall. Built with bricks and temporary plastered it has always been criticized…


Jonson, Cura dei monumenti, Stockholm 1986

Researched by Prof. Dr. Valentin Kockel



In the 18th century even the Carotti´s Cork model of the Colosseum found its way across the Alps in order to teach people about unknown culture and architecture. To get to those unknown historical spots the first tourists spent years for treveling but when they came back home their intellectual status had grown up and this was the key into a new age..01_Screenshot_20180607-222457.

So lets “hit the dusty trail” together with Cevin McCloud on his  GRAND TOUR OF EUROPE. In this 3rd episode of his travel documentation he takes us to Rome where we also can watch Dieter at his open air studio – in the Forum…



Luigi Carotti dusted the base of the Colosseum with cork powder. But during the years it disappeared and only a bit remained on the “twin model” at the Lindenau Museum.

Dieter does the same steps as Carotti but like in a “time machine” he erodes the surface to get a similar expression…


As we learn from Carottis other Colosseum model at the Lindenau-Museum the old master constructed its base from solid wood, which was the way to do at his time. The problem was that the wood “works” and damages the cork. Today we use plywood for a solid construction.

Dieter does so too but with respect to Luigi Carotti and his way to work he shows the same structure of the surface, even if this is not necessary…




The next step is to complete one of the six oval construction walls of the Colosseum. This is a very difficult step of reconstruction work because the new part must be fitted exactly between the existing elements.

02_20180531_135134REALM OF HISTORY


One third of the inner facade is lost and must be reconstructed. For this purpose Dieter has to get the cork in oval shape. He does this in the same way like the old masters did…


CUTTING THROUGH 18.05 (3)CUTTING THROUGH 18.05 (4)CUTTING THROUGH 18.05 (5)CUTTING THROUGH 18.05 (1)During the centuries the model was badly treated and broken parts where fitted incorrectly with the wrong glue. Dieter has to cut through the whole structure and work like a surgeon to stabilize the fragile cork and heal the wounded sections…


Restoring a ruined ruin…

for the second time Dieter Cöllen is going to restore the Colosseum – another cork model and masterpiece from Luigi Carotti (1842?). In 2017 Cöllen made his experiences with the one in the collection of the Lindenau-Museum in Altenburg/Germany.

This “twin” piece of a private owner is unfortunately in bad condition and it will take Cöllens entire knowledge and perfect cork material to bring it back to that ruin Carotti once created.

Starting with a solid base from plywood Cöllen reconstructs first the missing inner part of the arena.

Than the cork has to be “ruined” and colored with natural pigments even Carotti used at his time.

The last shots…

What else is more important than to finish a project with real emotional connection to the theme…

I did today and the model of the Wailing Wall is on its way to Berlin. Good luck…


Work is nearly done…


After spending lots of energie in reconstructing the missing part of the Coliseum, work is nearly done. The last act will be to color the raw cork with natural pigments like Luigi Carotti did in his time. Inspired by a walk through the beautiful park of the Lindenau-Museum  I am very optimistic to close the book as it has to be…



Just the Coliseum…

Starting restauration work at the beautiful Lindenau-Museum today. The cork model was made 1845 by Luigi Carotti. Dieter Cöllen wants the audience to look over his sholder and answers questions about his work and the forgotten technique of „Phelloplastik“  Lindenau-Museum

Come over!


See man at work: Dieter Cöllen on tour…

Lindenau-Museum, Altenburg

Foto: Punctum, Bertram Kober

Cork artist Dieter Cöllen will move his studio to the Lindenau Museum, Altenburg, for a week to do restoration work on a cork model of the Coliseum (Luigi Carotti, around 1845). On October 20th, 2017 from 3 pm to 6 pm and October 22th from 10 am to 1 pm. Interested museum visitors have the chance to look over the artits shoulder and learn more about the forgotten art of „phelloplastic“ and the difficulties of cork restoration.



The Mughrabi Gate

The Mughrabi Gate is located on the north side of the Wailing Wall, directly over the Herodian-period gate known as Barclay´s Gate. Over the years the ground level outside Barclay´s Gate rose by many meters above its threshold and was finally walled up in the 10th century. Later in the 12th century a new gate called Bab al-Maghreb was installed at the level of the Temple Mount esplanade. The Gate is open until today and the only entrance to the Temple Mount for non-Muslims.

Here, Dieter Cöllen is going to create a miniature of the gate (scale 1:75) in order to integrate it later into the wall.

Dierter Cöllen, Korkmodell Klagemauer, Mughrabi Gate (3)

One year after it´s destruction. „Reconstruction“ of the Baal-temple in Palmyra finished…

After three months of intensive work, Dieter Cöllen has now completed the cork model of the Baal temple.

He is delighted by the extensive press response – Der Spiegel, NRT , Video – as well as by the positive appraisals of many archaeologists and contemporary witnesses. In his Blog he tried to report on the progress of the works in real time, and put them up for discussion. Even for the invisible details he kept to the archaeological stone plans, so that the model can be used for studying the structural design. However, Dieter also placed great value on colour reproduction, in order not to disregard emotional concerns.

Dieter convinced that the physical presence of this monument is crucial for understanding its history, as well as our own cultural roots.

The catalyst for Dieter´s efforts was his initially powerless rage over such senseless destruction, which he was soon able, however, to transform into creative energy. The model was therefore created entirely independently and without third-party, financial support.

After all that ‘constructive’ time, Dieter now has to give some serious thought to his livelihood again. He has two visions for this:

  1. „I also understand my work to be the result of my personal resistance, I can imagine creating editions that can be acquired by collectors with the same interests, so this way they can become a driving force and support for a shared idea.“

  2. „The continuing destruction of ancient monuments could demand a gallery of our cultural heritage that is lost or deserving of protection. Models of these objects could be placed in context with their past, as well as with current developments, and lead to improved understanding of history.“

„Of course I would be pleased to hear your ideas on this subject as well. My urge to continue is unbridled, but of course I dream of being able to work towards a greater goal…“01.08 (8).JPG

Dieter Cöllen 28.08.2016