The Vasca was a large rectangular enclosure of about 85 feet by 120 feet. As shown in the model, 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. 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 (say, the bottom right in the model) and exited at the opposite corner (bottom left in the model) after making an offering at the temple, which once contained a cult statue.