Lago Miseno

The Piscina Mirabilis (Latin "wondrous pool") is an ancient Roman cistern on the Bacoli hill at the western end of the Gulf of Naples, southern Italy. It was one of the largest ancient cisterns. It was built under Augustus as suggested by the building technique of opus reticulatum used in the walls.The cistern was dug entirely out of the tuff hill and was 15 metres (49 ft) high, 72 metres (236 ft) long, and 25 metres (82 ft) wide.