tunnel system
Subterranean passage complex
A tunnel system is a network of underground passages, whether natural formations in rock or deliberately constructed for transportation, utilities, warfare, or concealment.
The term applies to subway networks, mining operations, animal burrows, and clandestine routes: The VC tunnel system at Cu Chi stretched for over 250 kilometers.
Smugglers used an elaborate tunnel system beneath the border.
- undergroundBelow ground or countercultural
- passageSegment of text
- secret passageConcealed route through structure
- subwayUnderground transit passage
- burrowAnimal's dug dwelling
labyrinth · warren · ant colony · excavation · mine · catacomb · network · shaft · air shaft · ventilation · escape · bunker · metro · sewer · digging · darkness · echo · concrete
- secret passagessecret passage, hidden door, hidden panel, hidden staircase, secret door
- transportation infrastructurehighways, highway design, road design, road network, rail network
- guerrilla warfareguerrilla, guerrilla tactics, guerrilla fighter, partisan, partisan warfare
- Teotihuacanfeathered serpent, mural paintings, urban grid
- termite moundstermite mound, mound, nest, colony, chamber
- fortificationsfort, fortress, fortresses, citadel, citadels
tunnel systemelevated railway
Raised urban train system
aerial tramway · monorail · elevated highway · viaduct · monorail system
tunnel, system, tunnels, tunneled, tunneling, tunneller, tunnellers, systems, systematic