The core of any Greek theater is the orchestra, the “dancing place” of the chorus and the chief performance space. It was a flat, circular space where the dancers and actors would interact and there was often an altar built in the center. Almost nothing remains from the fifth-century structure of the Theater of Dionysus in Athens, but later theaters suggest that the original orchestras were full circles; for example, this aerial view of the theater at Epidaurus. The earliest orchestras had dirt floors, however as theatre developed, orchestras began to be paved with marble and other expensive and lavishing materials.
The audience sat in the theatron, the “seeing place,” on semi-circular terraced rows of benches (in the earliest theaters these were wooden; they were later built of stone). The Greeks often built these in a natural hollow (a koilon), though the sides were increasingly reinforced with stone. For instance, the view of Epidaurus Theatre shows us that if a spectator was sitting at the back of the theatre, it was quite possible to see the orchestra as well as the actors interacting there. The theatron consisted of stairs that mounted to the highest levels that divided the sections of seats into wedges. The Epidaurus theatre has 55 semi-circular rows, providing an estimated seating capacity of 12,000, - 14,000. Although the name theatron suggests an emphasis on sight, in reality actors and chorus would look rather small even from seats only part-way