amphitheatre
Amphitheatre (noun) means an open, outdoor theatre (which may be a theatre in the round, or have a stage with seating on only one side), especially one from the classical period of ancient Greece or Rome, or a modern venue of similar design.
Etymology
From Latin amphitheatrum, from Ancient Greek ἀμφιθέατρον (amphithéatron) from ἀμφί (amphí, “on both sides”) + θέᾱτρον (théātron, “theatre”).