The Roman cryptoporticus of Aosta

You go down into it from Piazza Papa Giovanni XXIII, next to the cathedral. The cryptoporticus is a large, half-buried gallery covered by vaults. It dates from the end of the 1st century BC, shortly after the founding of Augusta Prætoria. It was part of the forum, the great public square of the Roman town.

A U-shaped plan

The cryptoporticus consists of three galleries laid out in a U. They surrounded on three sides the terrace on which the sacred area of the forum stood. The longest gallery is almost 90 metres long.

What were these galleries for?

Archaeologists do not all agree. Several uses are possible:

• supporting the terrace on which the forum rested;
• serving as a cool store for foodstuffs;
• providing a covered walkway, sheltered from rain and sun.

Roman concrete and dressed stone

The building work was part of the major projects launched when the town was founded, in 25 BC. The names of the architects are not known. Nor do we know exactly who worked on the site.

The walls are built in opus caementicium, a mixture of mortar and stones and the forerunner of concrete. The barrel vaults are reinforced with arches of dressed stone. Small openings at the top of the walls let in light and air. The floor is paved with slabs of local stone.

Brought back to light

For centuries the galleries lay buried beneath the buildings of the town. They were rediscovered in the 19th century. Excavations and restoration work then made it possible to open them to the public. Today you walk through them in the half-light, beneath the vaults, below the level of the square.

Roman cryptoporticus of Aosta
Piazza Papa Giovanni XXIII
11100 Aosta (AO)
Telephone: (+39) 3 357 981 505
Open daily, 9 am–7 pm