http://agathe.gr/democracy/the_ekklesia.html
The Ekklesia (Citizens' Assembly) All Athenian citizens had the right to attend and vote in the Ekklesia, a full popular assembly which met about every 10 days. All decrees (psephismata) were ratified ... Athens, Agora Museum. The model shows the Pnyx in its first phase, generally associated with the Kleisthenic reforms. The natural hill slope was used to form an auditorium, and there was a retaining wall at the bottom which supported the terrace where speakers stood. ... Athens, Agora Museum IL 656, 819, 893, 944, 1146, 1173, 1233.