地下回廊

thumb|right|Cryptoporticus of Nero|Emperor Nero at [[Domus Transitoria, Palatine Hill]] In Ancient Roman architecture a cryptoporticus (from Latin crypta and porticus) is a covered corridor or passageway. The usual English is "cryptoportico". 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.