Terme di Achille

Beneath Catania's Piazza del Duomo, a surviving portion of the Achillian Baths reveals Roman architecture of exceptional scale for the city: locally the largest known ancient thermal complex, dated by most scholars to the 4th century AD, though some scholars link it to an earlier structure attributed to governor Lusio Labieno. The complex's name comes from an inscription on a 5th-century marble slab, now held in the Castello Ursino civic museum, which historians variously connect to its builder or to a lost statue of the Greek hero Achilles.

Buried by the earthquakes of 1169 and, more decisively, 1693, the remains were only cleared in the 18th century by the Prince of Biscari, before being further uncovered by Catania's citizens during later excavations. Today the site is reached through a barrel-vaulted corridor cut between the cathedral's foundations, via a descending ramp to the right of its facade — an underground passage that leads straight into ancient Sicily's thermal history.