This detailed account of excavations centered on the Tholos reveal this important building to have been the headquarters of the prytaneis, leading Athenian councillors. The book surveys the earlier buildings on the site, dating from the 6th century B.C., before focusing on the round building itself—a remarkably stable structure that was used for almost one thousand years. The Tholos itself was a surprisingly unpretentious structure with an inner diameter of less than 17 meters. Its walls were of crude brick resting on three or more courses of poros blocks. There was a main door on the east and a small door leading to a kitchen to the north.