Aqua Claudia was an ancient Roman aqueduct that was begun by Emperor Caligula in 38 AD and finished by Emperor Claudius in 52 AD.
The total length was approximately 69 kilometres, most of which was underground. The flow was about 190,000 cubic metres in 24 hours. Directly after its filtering tank, near the seventh mile of the Via Latina, it finally emerged onto arches, which increase in height as the ground falls toward the city, reaching over 30 metres.
Nero extended the aqueduct with the Arcus Neroniani to the Caelian hill and Domitian further extended it to the Palatine after which the Aqua Claudia could provide all 14 Roman districts with water. The section on the Caelian hilll was called arcus Caelimontani.
The aqueduct went through at least two major repairs. Tacitus suggests that the aqueduct was in use by AD 47. An inscription from Vespasian suggests that Aqua Claudia was used for ten years, then failed and was out of use for nine years. The first repair was done by Emperor Vespasian in 71 AD; it was repaired again in 81 AD by Emperor Titus.
Alexander Severus reinforced the arches of Nero (CIL VI.1259) where they are called arcus Caelimontani, including the line of arches across the valley between the Caelian and the Palatine.
The church of San Tommaso in Formis was later built into the side of the aqueduct.
References:The Pilgrimage Church of Wies (Wieskirche) is an oval rococo church, designed in the late 1740s by Dominikus Zimmermann. It is located in the foothills of the Alps in the municipality of Steingaden.
The sanctuary of Wies is a pilgrimage church extraordinarily well-preserved in the beautiful setting of an Alpine valley, and is a perfect masterpiece of Rococo art and creative genius, as well as an exceptional testimony to a civilization that has disappeared.
The hamlet of Wies, in 1738, is said to have been the setting of a miracle in which tears were seen on a simple wooden figure of Christ mounted on a column that was no longer venerated by the Premonstratensian monks of the Abbey. A wooden chapel constructed in the fields housed the miraculous statue for some time. However, pilgrims from Germany, Austria, Bohemia, and even Italy became so numerous that the Abbot of the Premonstratensians of Steingaden decided to construct a splendid sanctuary.