By GIADA ZAMPANO

ROME (AP) — Archaeological excavations near the Vatican uncovered the remains of an ancient garden overlooking the right bank of the Tiber River that was likely owned by Roman Emperor Caligula, Italy’s culture ministry said Thursday.

The discovery was made during construction work to create a pedestrian piazza linking Castel Sant’Angelo to St. Peter’s Basilica and its Via della Conciliazione boulevard, some of Rome’s most visited tourist sites.

In ancient times the area housed prestigious imperial residences overlooking the Tiber with spectacular porticos, promenades and gardens. What remains underground are a travertine wall, the foundations of a colonnaded portico and a garden, the ministry said.

The excavations also uncovered a lead water pipe stamped with the name of the owner of the water supply and likely of the garden.

The details point to Caligula, son of Germanicus and Agrippina the Elder, and emperor of Rome from 37 to 41, the ministry said, adding that there are literary references that seem to confirm the connection of the site to Caligula.

The excavation also revealed an important series of figurative terracottas used to decorate roofs, with unusual mythological scenes, reused as covers for the sewers, but originally probably made for the covering of some structure in the garden, the ministry said.

The construction project is part of the Vatican’s 2025 Jubilee, a holy year that is expected to draw some 32 million pilgrims to Rome. The runup to the Jubilee has involved launching dozens of long-delayed construction projects, including the 79.5 million euro piazza, with a tunnel below it redirecting traffic underground.

The project, located at Piazza Pia, is expected to be completed by December.