The NE-SW-trending Burdur-Fethiye fault zone is one of the major active fault zones of southwestern Turkey and the ancient city of Cibyra is located on this zone. Segments of the Burdur-Fethiye fault zone have ruptured in the historical period and during the 20th century. A detailed investigation in the ancient city of Cibyra showed the presence of faults sinistrally offset sitting rows of the stadium up to 50 cm. In addition, there are broken corners of blocks, collapsed walls, broken columns, and tilted and toppled blocks in existing major buildings in the city centre. Field observations showed that fractures and associated damage at Cibyra were produced by a post-Roman earthquake, possibly during the 417-A.D.-earthquake which had an intensity of 9 on the MSK scale. (C) 2001 Editions scientifiques et medicales Elsevier SAS.