access aisle alley ambulatory aperture apse arcature arch arched roof archway areaway artery atlas avenue breezeway camber caryatid ceilinged roof channel cloister colonnade colonnette column communication concameration concha conduit connection corridor cove covered way cupola defile dome exit ferry ford gallery geodesic dome hall hallway igloo inlet interchange intersection junction keystone lane loggia ogive opening outlet overpass pass passage passageway pergola peristyle pier pilaster pillar portico post railroad tunnel skewback span telamon traject trajet tunnel underpass vault vaulting voussoir