An amphitheatre was a type of outdoor theatre. It was particularly favoured by the Romans as a place of gladiatorial combat.

In July 64 Ian Chesterton was once forced to fight another gladiator for the amusement of Caesar Nero in an amphitheatre. Chesterton only narrowly escaped having to fight a lion there. (TV: The Romans)

In 120, the Tenth Doctor faced a lion, a tiger and a bear in the Flavian Amphitheatre. (PROSE: The Stone Rose)

The ancient Greeks used amphitheatres for performing plays. According to the Fourth Doctor, the Greeks would put on plays to mark a festival. There would be three plays in one day; the last was usually a comedy. When the Doctor and Leela visited Athens, they saw a comedy by Aristophanes in the amphitheatre. (PROSE: The Brain of Socrates)

The Sensorites imprisoned the First Doctor in an amphitheatre on their world. (PROSE: The Monsters from Earth)
