Aqua Traiana

The Aqua Traiana is a Roman aqueduct originally constructed under Emperor Trajan in the early 2nd century AD to supply Rome with water from sources west of the city. Its course and infrastructure were an important part of Rome’s water supply system.

Remains of the aqueduct survive in places as visible channels, masonry works, and sections of conduit outside the modern city. Parts of its route and associated structures have been identified near the sources around the Bracciano area and along the western approaches to Rome.

Built under Trajan to tap springs west of the Tiber, the aqueduct supplied water to districts on Rome’s western side. It fell into disuse in the medieval period but was substantially restored in the early 17th century by Pope Paul V; that restoration became known as the Acqua Paola and is associated with the monumental fountain on the Janiculum.

The Aqua Traiana drew water from springs and catchments in the hills northwest of Rome, including the area around Lake Bracciano, and ran toward the western sectors of the city.

• Date and purpose: Built in the reign of Emperor Trajan in the early 2nd century AD to bring water to Rome from sources west of the city.
• Restoration: Significantly restored in the early 17th century by Pope Paul V, with the restoration known today as the Acqua Paola fountain on the Janiculum.