Like the Doric Nymphaeum, it faces Monte Cavo (ancient mons Albanus).The Nymphaeum is rather irregular in shape as it most probably originates from a “pozzolana quarry”. It is arranged over several rooms, the largest being the central hall that features a circular pool dug out of the ground with a diameter of around 17 meters, and which still shows traces of its mosaic decorations.This was also included in the large Domitian Imperial Villa of the 1st century AD and was discovered halfway through the 19th century during clandestine excavation work.Several clues show how, at a certain point, this monument must have been used as thermal baths, first by Domitian and after by Pope Alexander VII Chigi. It was furthermore used as a shelter for the boats of the emperor’s naumachias or as a pathway for the Pope to reach the waters of the lake. Most of the ruins from the Nymphaeum found during the excavations of Cardinal Giustiniani are preserved and displayed in the Antiquarium of Villa Barberini, while others have gone missing.
Better known as Diana's Baths, it is located on the west side of Lake Albano halfway between the Doric nymphaeum and the Emissary.