SIEM REAP – Every ancient monument is unique and each represents specific challenges which demand specific approaches. Delicate, fragile, and culturally valuable, the art of preserving historical stone assets requires multidisciplinary skills to develop conservation concepts based on the needs of each monument. From desalination to consolidation and more, conservation scientists have created ways to make ancient sites stronger as they age over the centuries.

Watch the interview on YouTube below:

Since 1995, Professor Hans Leisen, who heads the German Apsara Conservation Project (GACP), and his team of local and international experts have preserved and strengthened the many deteriorating stones, ancient statues and bas-reliefs in the Angkor Park and especially Angkor Wat, a region rich in historical assets.

In this second part of a two-hour interview, Professor Leisen explains to Cambodianess how he and his team preserve Angkorian monuments and that unsatisfied research outcomes can be converted into opportunities.

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Background of the Conservation

The GACP is cooperating closely with the APSARA National Authority and UNESCO. Since 2020, the GACP team has been integrating into the APSARA authority within the framework of the APSARA-GACP cooperation project “German APSARA Restoration and Conservation Project GARCP”.

In 1997, GACP started with research, documentation and conservation of the precious decorations at Angkor Wat.

Conservation requires the exact knowledge of the materials - stone, brick and stuccoes - and the causes of deterioration. In the case of the stone reliefs, the extreme scale formation endangers the floral decorations and the mythological memory of the narrative reliefs.

Step-by-step documentation, research and practical testing paves the way for a sustainable conservation concept that satisfies the aesthetics appearance of the high-ranking works of art and the scientific approach, which is congruent with the current international state of the art.

Conservation materials are optimised and adapted to the needs of the monument. For stone conservation, the tetra-ethoxy-orthosilicate (TEOS) modular system is applied while for the stucco conservation lime products are developed.

At Angkor Wat temple, most reliefs are maintained and conserved. Other conservation work activities are carried out in more than 25 temples in the Angkor Park and beyond for example in Bakong and Preah Ko temples - where stucco remains and sandstone elements are conserved - as well as in many other sites in the Angkor Park, Koh Ker, and Sambor Prei Kuk and on Kulen mountain.

The research of wall paintings and polychrome decorations in the brick temples in Cambodia, construction and stone quarrying techniques are other topics of the Khmer-German GACP cooperation team.

The project is funded by the Cultural Preservation Programme of the German government, the TH Koln and FAKT.