underground tunnel
Buried transit corridor
An underground tunnel is a passage constructed beneath the earth's surface, typically for transportation, utilities, or access between locations.
The phrase is technically redundant—tunnels are by definition underground—but appears in contexts emphasizing subterranean location: The escape route used an underground tunnel beneath the prison walls.
- subwayUnderground transit passage
- passageSegment of text
- secret passageConcealed route through structure
- burrowAnimal's dug dwelling
- rat holeSqualid, cramped dwelling
crawl space · shaft · excavation · catacomb · mine · bunker · bomb shelter · sewer · metro · labyrinth · darkness · damp · dig · dig site · bore · storm drain · vault · escape
- airportsairports, airport, terminals, terminal building, runway
- mining townsaloon, general store, mine shaft, gold pan, prospector
- secret passagessecret passage, hidden door, hidden panel, hidden staircase, secret door
- insect habitatsanthill, beehive, hive, nest, cocoon
- fortificationsfort, fortress, fortresses, citadel, citadels
- capitolscapitol, state capitol, statehouse, Capitol dome, Capitol Hill
underground tunnelelevated railway
Raised urban train system
skyway · overpass · sky bridge · elevated walkway · elevated highway
underground tunnelbridge
Structure spanning an obstacle
overpass · viaduct · flyover · suspension bridge · footbridge
underground, tunnel, under, ground, undergrounds, tunnels, tunneled, tunneling, tunneller