The Nymphaeum is one of the symbols of Genazzano and was created at the beginning of the sixteenth century by the Colonna family while structuring a garden in the valley of the Soglia downstream, along the road that led to Paliano. This was the period of realization of grand gardens in many palaces, including the Vatican gardens, and the Colonna wanted to do ‘grand’ structures, building a park with a lake, originally on four levels, and a nymph.
The artistic centre of the park was a grotto built in the style of the Baths of Diocletian, or Basilica of Maxentius, which is attributed to Bramante. The architect in those years had also designed a church in nearby Capranica Prenestina. The nymphaeum is a building with a loggia facade on the long side and apses on the short sides. It consists of a rectangular space covered with vaults adorned with arches and openings, behind which is located an octagonal shaped hall with a spa at the centre for use as a bath.
The hall has seats to relax and enjoy the cool water. But by 1540, Ascanio Colonna, lord through a period of crisis with popes, who were ready to seize the assets, transformed the garden into vegetable gardens given in perpetual lease. The nymph was even a stable for cows until the eighteenth century. In 1703 an earthquake caused the collapse of the vault of the ceiling.