The south half of the west side was given over to the major administrative buildings used to run the Athenian democracy (Fig. 14). The buildings are poorly preserved, but the identifications are secure thanks to the account of the traveler Pausanias, who visited Athens in the years around A.D. 150.
The Tholos, recognizable by its round shape, served as the headquarters of the prytaneis (executive committee) of the boule (senate of 500), according to Aristotle (Ath. Pol. 43.3). Here the fifty senators were fed at public expense, and at least seventeen spent the night in the building, available to deal with any emergency, whatever the hour. In a sense, then, the Tholos represents the heart of the Athenian democracy, where citizens serving as senators could be found on duty twenty-four hours a day.
Built around 470 B.C., the building was an unadorned drum, with six interior columns supporting a conical roof of large diamond-shape terracotta roof tiles (Fig. 15). The round form of the building is ill-suited for its primary function as a dining-hall and it may be that the usual Greek practice of reclining on couches during meals was abandoned here in favor of sitting on a simple bench. Wine jars and cups labeled as public property were found around the building (Fig. 16).