PAT 99 course participants at the Site Museum of Chan Chan, Peru, review construction techniques for earthen architecture. Chan Chan was an earthen city constructed and occupied by the Chimu people between the 10th and 15th centuries. Photo: Hugo Houben.

Wall supports stabilize the remains of adobe barrack walls at historic Fort Selden in New Mexico. This 19th-century fort—abandoned by the U.S. Army in 1891—has been the site of earthen architecture preservation research by the Museum of New Mexico State Monuments, research in which the GCI has participated. Photo: Erica Avrami.

East face of the Triple Arched Gate at Tel Dan in Israel. This 3,700-year-old mud brick gate is one of the earliest known examples of an arched structure. The GCI undertook extensive documentation of the site as part of a project with the Israel Antiquities Authority. Photo: Erica Avrami.

PAT 96 course participants construct an adobe wall near the archaeological site of Huaca del Sol in the Moche Valley, La Libertad, Peru. Photo: Leslie Rainer.

Decorated earthen surface at the site of Huaca de la Luna in the Moche Valley, La Libertad, Peru. Photo: Erica Avrami.

PAT 99 course participants study conservation of decorated surfaces at the site of Huaca de la Luna in the Moche Valley, La Libertad, Peru. Photo: Erica Avrami.

Conservation challenges in the Tschudi Palace at the site of Chan Chan in La Libertad, Peru. Photo: Erica Avrami.

Participants in the PAT99 course field lab at the Site Museum of Chan Chan, Peru, evaluate the efficacy of renders and capping in the preservation of earthen walls. Photo: Hugo Houben.

Conservation of decorated surfaces at the site of Huaca de la Luna in Peru. Photo: Hugo Houben.