The Vasca was a large rectangular enclosure of about 85 feet by 120 feet. A 12-foot-wide roofed portico, open to the inside, surrounded a bathing area paved with inverted ceiling tiles. The bathing area was fed by an underground spring, labeled “Sorgente” on the plan. Today the stream bed can still be seen in the Vasca.
Excavators also uncovered a small temple (20 feet wide and 10 feet deep), or sacellum, at the western side of the pool. Ailing visitors likely entered the pool at one corner and exited at the opposite corner after making an offering at the temple, which once contained a cult statue.