An amphitheatre (U.S. English: amphitheater) is an open-air venue used for entertainment, performances, and sports.[2] The term derives from the ancient Greek ἀμφιθέατρον (amphitheatron),[3] from ἀμφί (amphi), meaning "on both sides" or "around"[4] and θέατρον (théātron), meaning "place for viewing".[5][6]
Ancient Greek theatres were typically built on hillsides and semi-circular in design. The first amphitheatre may have been built at Pompeii around 70 BC.[7] Ancient Roman amphitheatres were oval or circular in plan, with seating tiers that surrounded the central performance area, like a modern open-air stadium. In contrast, both ancient Greek and ancient Roman theatres were built in a semicircle, with tiered seating rising on one side of the performance area.
Modern english parlance uses "amphitheatre" for any structure with sloping seating, including theatre-style stages with spectator seating on only one side, theatres in the round, and stadia. They can be indoor or outdoor.