An amphitheatre (British English) or amphitheater (American English; both ˈæmfᵻˌθiːətər) is an open-air venue used for entertainment, performances, and sports. The term derives from the ancient Greek ἀμφιθέατρον (amphitheatron), from ἀμφί (amphi), meaning "on both sides" or "around" and θέατρον (théātron), meaning "place for viewing".
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.
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.
landforms and rock formations of similar shape are sometimes known as natural amphitheatres.
Roman amphitheatre
About 230 Roman amphitheatres have been found across the area of the Roman Empire. Their typical shape, functions and name distinguish them from Roman theatres, which are more or less semicircular in shape; from the circuses (similar to hippodromes) whose much longer circuits were designed mainly for horse or chariot racing events; and from the smaller stadia, which were primarily designed for athletics and footraces.
Roman amphitheatres were circular or oval in plan, with a central arena surrounded by perimeter seating tiers. The seating tiers were pierced by entrance-ways controlling access to the arena floor, and isolating it from the audience. Temporary wooden structures functioning as amphitheaters would have been erected for the funeral games held in honour of deceased Roman magnates by their heirs, featuring fights to the death by gladiators, usually armed prisoners of war, at the funeral pyre or tomb of the deceased. These games are described in Roman histories as munera, gifts, entertainments or duties to honour deceased individuals, Romes' gods and the Roman community.