The Terme dell’Indirizzo (to give them their Italian name) stand near the centre of modern Catania (access today is from Piazza Currò) on Sicily's E coast (fig. 1). They are not a new discovery: the ancient structure remains as a standing building. It is not just the best-preserved Roman bath-building in Sicily; it is among the best-preserved examples of its type anywhere in the empire, the original roofs of nearly every surviving room being, remarkably, intact. Despite this, the structure is little known, mainly because it has been publicly accessible only on sporadic occasions. Our purpose is to make the baths better known by presenting a modern survey of the standing structure, with new information above all on the building's geometry and construction techniques, and by setting it in the context of bath-buildings in Sicily and the wider empire.