Britain
Caves
Karst Areas
Karst Features
Springs
Gorges
Mines
Subterranea
Battle of Britain Control Room
Beer Quarry Caves
Bruce's Cave
Cabinet War Rooms
Caldecotte Project
Cavern Club
Channel Tunnel
Chislehurst Caves
Churchill's Secret Bunker
Crowborough Caves
Cruachan Power Station
Culver Hole
Dewstow Gardens and Grottoes
Dorking Caves
Dudley Canal Tunnels
Dunaskin Open Air Museum
Essex Secret Bunker
Exeter's Underground Passages
St Fillan's Cave
German Underground Hospital
German Military Underground Hospital
German Naval Signals Headquarters
Gilmerton Cove
Greenwich Foot Tunnel
Hack Green
Halliggye Fogou
Hawkstone Park
Hellfire Corner
Herts Young Mariners Base
Humphrey Kynaston's Cave
Kelvedon Hatch
La Valette Underground Military Museum
Llewelyn's Cave
London Underground
Maeshowe
Margate Caves
Margate Shell Grotto
Mary King's Close
Mine Howe
Netherton Tunnel Branch Canal
Noirmont Command Bunker
Caves of Nottingham
Ossian's Cave
Porthcurno Telegraph Museum
Redcliffe Caves
Royston Cave
Scotland's Secret Bunker
Scott's Grotto
Shunt
London Silver Vaults
St Margaret's Cave
St Peter's Bunker Museum
Standedge Tunnel
The Bunker
Tilly Whim Caves
Tregiffian Burial Chamber
Victoria Tunnel
Vortigern Cave
West Wycombe Caves
Western Approaches Command Centre
Williamson's Tunnels