Cryptoporticus

In Ancient Roman architecture a cryptoporticus (from Latin crypta and porticus) is a covered corridor or passageway.

The cryptoportico is a semi-subterranean gallery whose vaulting supports portico structures aboveground and which is lit from openings at the tops of its arches.

The shade and semi-excavated site of a cryptoportico provided cool and moderated temperatures useful for storage of perishables, while it offered a level and slightly raised podium for the superstructure.

Later, the Bishop's Palace (still standing today as Machado de Castro National Museum) was built using the platform created by the structure thus preserving it in perfect condition.

The cryptoporticus of Arles, dating from the 1st century BC was built as foundation for the forum, which has since been replaced by the Chapel of the Jesuit College and the city hall.