Piscina Mirabilis

The Piscina Mirabilis (Latin for "wondrous pool") is an Ancient Roman cistern on the Bacoli hill at the western end of the Gulf of Naples, southern Italy. It ranks as one of the largest ancient cisterns built by the ancient Romans, compared to the largest Roman reservoir, the Yerebatan Sarayi (aka Basilica Cistern) in Istanbul. The adjective Mirabilis was given by the 14th c. Tuscan poet Francesco Petrarca on one of his visits.