The Propylaea, the monumental gate building to the Athenian Acropolis, occupies the summit of the west slope, the only negotiable access to the top of the rock. The building process started in 437 B.C. and came to an end after a time period of considerable but unknown length. The building that was finally accomplished, comprised a central structure and two lateral wings facing each other. This was only a reduced version of the plan drawn up originally by the architect Mnesicles. Even so, it inspired the admiration of his contemporaries and generations to come, because it had no precedent. With the Propylaea, the concept of architecture was recast; a new building type was invented and implemented, where architectural language, secular purpose, and function dictated a setting and created an architectural landscape that finalised a sanctuary.
The whole complex proves Mnesicles' pioneer genius not only regarding architectural design, but engineering practices as well. Ever since its erection, it generated admiration and inspired important architectural schemes in Antiquity, but also in the modern era, beginning in the Renaissance and continuing to the twentieth century.
For almost sixteen centuries, that is, from AD 267, to the establishment of the modern Greek state, in 1830, the Acropolis was a fortified castle and the Propylaia was incorporated into the fortifications. In the Middle Ages, the Propylaea functioned as an archbishop's residence and then as a fortified palace. In 1640, while Athens was under Ottoman rule, the Propylaia was used as storage space for gunpowder. An explosion occurred causing damage to the original structure, particularly in the superstructure of the central building.
The first recorded and organised restoration carried out on the Propylaia was conducted by Nikolaos Balanos, between 1909 and 1917. It was concentrated on the Central Building which had suffered the most damage. It utilised most of the surviving original material in the superstructure of the east portico and of the west hall. The ample use of iron as a bonding agent soon caused serious damage to the marble, which made a subsequent restoration inevitable. The original aim of the Propylaea Restoration Project in 1986 was to face up to the dramatic fragmentation of the beams and coffers in the ceiling restored by Balanos. The qualitative and quantitative characteristics of the problems were revealed gradually during implementations carried out in two preliminary stages: In 1990-1993, the whole of the ceilings restored by Balanos were dismantled. In 1997-2001, the east end of the south wall was dismantled, treated and reassembled.
The final stage of the Project that received an award in 2013, started with the dismantling of the superstructure in February 2002. The project was carried out by the Acropolis Restoration Service under the scientific supervision of the Committee for the Conservation of the Acropolis Monuments (ESMA, Hellenic Ministry of Culture). The project budget totalled 7.398.846euro; and it was co-funded by the Hellenic Republic and the European Union.
In May 2003 all the blocks had been dismantled and organized in the work site. Restoration started immediately and the work was completed in December 2009. By then, 301 blocks had been dismantled, conserved and reassembled; another 66 blocks had been restored for the first time, above the central passageway, thus allowing more of the famous ceilings of the Propylaia to be seen. In the end, 367 architectural pieces were reset in their original positions, their weight varying from 0.5 to 11 tons.
This restoration benefited immensely from the new detailed study of the building conducted in situ, and from the careful identification of the original fragments of the ceilings' beams and coffers. Every step in treating and restoring the monument was scrupulously documented in text, drawings and photographs for each architectural component and for the building as a whole.
Particular attention was paid so that the original architectural details and the texture of the marble surfaces were reproduced with absolute accuracy. This approach was exemplified by the reconstruction of the two Ionic capitals, which were studied and restored from full scale drawings, for the first time in such detail, before being carved in new marble. The sculpting work on the capitals was produced by the hands of skilled craftsmen, while the accuracy in the reproduction of each detail was monitored and ensured in every stage of the procedure.
Beyond the high quality of the details, the new restoration of the superstructure of the central building of the Propylaia is distinguished a) for having applied modern technology very carefully, in order to replicate the structural principles of the technology developed by the ancient builders; b) for having restored the correct dimensions to each block and to the building as a whole; c) for preserving traces of the original materials from the several structural phases of the monument.
The characteristic methods of operation can be summarised as follows: the rusty iron was removed and titanium reinforcements were used instead, this time integrated in a structural system designed so that the main principles of the classical structural technology are reproduced. For this purpose, titanium rods were installed inside each block, to join the original fragments and/or new marble supplements, thus restoring to the blocks the original solidity and individuality; the consolidated blocks were built into the wall with no mortar, with titanium clamps and dowels sheathed with cement instead. Parallel to the implementation works, investigation of the original material was continued, resulting in new discoveries and better knowledge of the monument. This allowed:
a) the correction of mistakes in the Balanos restoration;
b) the restoration of more parts of the superstructure in comparison to the Balanos restoration;
c) the restoration of the original dimensions of the superstructure with important aesthetic results;
d) and the recovery of much of the fine detailing of the architectural forms and of the dignity of the building as a whole.
The principles followed in all the projects on the Acropolis were here applied with a meticulous care throughout the process of study and implementation, making the Propylaea Restoration Project outstanding in a European context and, thus, a model for restoration projects on European monuments with similar structural characteristics.
The restoration of the superstructure of the Propylaia's central building is an interdisciplinary achievement. None of the fine qualities of this implementation would have taken place without the unanimous collaboration of the team which I had the privilege to direct, comprised of architects, civil engineers, archaeologists, draughtsmen, marble craftsmen and conservators. It is important to stress that it is through the hands of our devoted marble craftsmen, that what we had visualized through scientific investigation and architectural drawings, was made real. It is a wonderful esprit de corps that has made Mnesikles's mastepiece breathe again.
We pride ourselves on having restored the superstructure and the famous ceilings, in a manner that allows a new appreciation of the complex character and the harmonious proportions of this unique monumental space. The architecture of the Propylaea, while retaining the majestic charm of the ancient ruin that it is, has emerged more coherent as a whole, presenting the west end of the Acropolis with an outline much more dignified than before.