Baths of Caracalla

Completed under Emperor Caracalla in AD 216, these imperial baths could serve 1,600 bathers at once across a 25-hectare complex of hot, warm, and cold rooms, gymnasia, libraries, and gardens. Beneath the floors, an underground labyrinth housed 50 furnaces and a Mithraeum, tended by hundreds of slaves who heated water and stoked the hypocaust. The vaulted halls soared 40 metres, clad in coloured marble, mosaics, and colossal statues like the Farnese Hercules. A ruptured aqueduct during the Gothic Wars of the 530s ended their use. The towering brick ruins now host summer opera performances beneath the open Roman sky.