The foundation of the Athenian Tholos is visible in the foreground, with the Acropolis visible in the background to the southeast [link]

Aside from the actual council chamber, the bouleuterion complex also included a buildling called the Tholos. The building is described as a tholos because of its circular shape, as tholos is the greek word for circle. It stood south of the original bouleuterion, and had a diameter of around 18.3 meters, with a wall about .7 inches thick. Also called the skias because of its cone-shaped roof, it was built around 470 BC by Kimon, to serve as a dining room for the members of the senate, or boule. At any point during the senate's session, the 50-man executive commitee, called pyrtaneis in greek, would be dined at public expense in the tholos. There is a small kitchen on the north side of the buildling, and six interior columns that serve as roof supports.

A buildling plan of the entire Bouleuterion Complex, c. mid 5th century [link]

It is notable that the cylindrical shape of the tholos is not conducive to the typical manner of dining on couches; the lack of straight walls and angles means that couches would not fit properly into the building. It is possible that the council members ate seated, however; in this case, a rounded bench could have been placed around the inside of the walls to easily accomodate the members of the pyrtaneis.

In addition to serving as a mess hall for the members of the council, the Tholos also served the function of a small-scale boarding house. At any time, at least one-third of the members of the pyrtaneis were expected to sleep in the Tholos so that they may be ready to deal with any unexpected issues. According to John Camp, "In a sense, the Tholos represents the heart of Athenian democracy, where at least seventeen citizens serving as senators could be found on duty at all times" (Camp 2001, p. 70).

The Tholos also served as a Bureau of Standards, housing an official set of weights and measures. These were inscribed with their weights, the words demosion Athenaion meaning "of the athenian public" and were decorated with different symbols for easier recognition.

References

Camp, John M. The Athenian Agora: Excavations in the Heart of Classical Athens. Thames and Hudson, London; 1992

Camp, John M. The Archaeology of Athens. Yale University Press, New Haven; 2001

O'Neil, James L. The Origins and Development of Ancient Greek Democracy. Rowman and Littlefield, Boston; 1995

Roberts, J.W. City of Sokrates: An Introduction to Classical Athens. Routledge, London; 1998

Thorley, John. Athenian Democracy. Routledge, London; 1996