How to get there:
At Poggio Murella proceed onto via del Greppo and then onto via dei Sassi Bianchi. Pass the cemetery and follow the road on the right. The structure will appear on your left.
When to visit: the site is free to enter and always open.
The Castellum Aquarum is a large cistern covered by barrel vaults supported by pillars with a capacity of 4,000 cubic meters (m 33,80 x 15, 35 x 8). The structure is part of a much larger complex, consisting of at least three tanks and various other structures, whose use has been the subject of considerable difficulty to discern. Some have speculated that it could have been a collection system to direct the water from some of the springs toward the town of Saturnia, or perhaps linked to a sacred area, or perhaps still have been the monumental water system for an imposing residence. Based on the masonry technique and small amount of material left, the complex is dated to the second half of the first century BC.