Piscina Mirabilis

Piscina Mirabilis is an underground water reservoir built by the Romans, located beneath modern-day Bacoli and offering visitors a direct view of ancient engineering. The structure contains massive pillars arranged in rows that divide the space into separate chambers and support the weight of the earth above.

The reservoir was built during the reign of Emperor Augustus and served as the end point of a system that transported water over long distances. It played a crucial role in supplying the Roman naval base and shows how the Romans managed water for military and urban purposes.

The name comes from Italian poet Francesco Petrarca, who admired the structure during his visit and called it remarkable. Visitors today can explore how this literary connection ties the ancient Roman world to the Renaissance period through the site's presentation.

Access is through a metal staircase at the northwest entrance, which protects the original Roman steps and makes the visit safe. Visitors should prepare to descend underground, so comfortable shoes and a flashlight or headlamp are helpful for exploring the underground space.

The underground reservoir was so large that it could support military operations for months at a time, earning a reputation as a marvel of water management. Roman engineers achieved this through a gravity-fed system that required no pumps, a remarkable feat of hydraulic engineering for the period.

Location: Bacoli

Part of: Aqua Augusta

GPS coordinates: 40.79519,14.08028

Latest update: December 6, 2025 16:02