Aqua Claudia

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 (100 ft)[citation needed].

The specus (channel) is about 1 m wide and is also built in opus quadratum, but with a very porous stone which is locally found as a layer immediately above the tuff on which the bridge rests.

The Anio Novus bridge, about 85 m long and about 10 m wide, has a few small arches except for the main high and narrow one for the Acqua Nera.

In the second half of the 1st century it was reinforced in opus mixtum, visible at the two east end buttresses.

At the beginning of the 3rd century nine rectangular buttresses were added at regular intervals on the north side while on the south side only three were added near the bed of the stream, later increased by five on the west bank in poor opus latericium and two on the east in opus mixtum.

Additionally, brick stamps from 123 AD testify to some restorations during the rule of emperor Hadrian[3].