Description

In the 4th c. AD, Emperor Maximian made two expansions to the 1st c. BC Roman walls to encircle two new areas of the city.

The most complete section of the addition to the walls on the west side can be seen in the garden of the Archaeological Museum (the ex-Monastero Maggiore). Here you can see the Asperto tower (named after the 9th c. Bishop Ansperto who was considered for centuries to have had it built) made from a pebble based cement and brick lining.

It has 24 sides and is probably still as high as it was originally (17 metres). It is one of the few visible Roman monuments that has remained whole to the present day.

A second, square tower stands in the museum's courtyard that was renovated in the Middle Ages. It was turned into the bell-tower for the monastery. It was also one of the two towers in the body of the construction at one end of the Roman circus from where the 2-wheeled chariots exited in races during the imperial era.