The low hill of the ancient acropolis, at the northern edge of town among olive trees, holds the main remains of ancient Sparta. It was first excavated by the British School at Athens from 1910, and work started again in the 1990s.
The biggest monument is the Roman theatre, built of white marble around 30–20 BC and one of the largest in Greece, for about 16,000 spectators. Higher up stood the Temple of Athena Chalkioikos, the most important temple of the city, once covered with bronze plates. There is also a mysterious circular building over 43 metres across and an early Byzantine basilica of the 6th–7th century.