The Hollow Mountain

Gibraltar holds about 55 km of tunnels inside a 6.7 km² rock, cut between 1782 and 1967. Almost all of it is military and sealed. This is what OpenStreetMap knows about it — and what it does not.

Dudley Ward Way — 693 mKeightley Road — 23 mKeightley Way — 405 mKeightley Road — 32 mBrian Navarro Way — 105 mLandport Tunnel — 35 mGavino's Court — 13 mWilliams way — 46 mMediterranean Steps — 29 mAROW Street Tunnel — 39 mAdmiralty tunnel — 957 mWilliams way — 30 mGreat North Road — 91 mGreen Lane — 24 mGreen Lane — 30 mWillis’s Road — 22 mKingsway — 61 mKingsway — 69 mLibrary Gardens — 13 mKingsway Tunnel — 352 mWellington Front — 14 mLibrary Gardens — 10 mKingsway Tunnel — 360 mFosse Way — 46 mRagged Staff Magazine — 659 mKingsway Tunnel — 285 mKingsway Tunnel — 27 mKingsway Tunnel — 13 mSt Michael's CaveGorham's CaveGoat's Hair Twin CavesBellman's CaveGovernor's Lookout BatteryDevil's Gap BatteryDouglas CaveHarding's BatteryRooke BatteryTovey BatteryLevant BatteryLord Airey's BatteryO'Hara's BatteryHayne's Cave BatteryJones' BatteryCastle BatteriesCouvreport BatteryOrillon BatteriesQueen Charlotte's BatterySpy Glass BatterySpur BatteryBuena Vista Barracks and BatteryBuffadero BatterySouth BatteriesWindmill Hill BatteriesWest BatteryEdward VII BatteryPrince Ferdinand's BatterySignal Hill BatteryGenoese BatteriesForbes' BatteriesMiddle Hill BatteryPrincess Amelia's BatteryPrincess Royal's BatteryPrincess Anne's BatteryZoca Flank BatteryLewis' BatteryEliott's BatteryWoodford's BatteryBatteryLord Airey's ShelterCoptic CaveEuropa Pass BatteriesMartin's CaveFig Tree CaveBoat HoistBennett's CaveVanguard CaveMonkey's CaveDevil's Tower CaveIbex CaveBeefsteak CaveHyaena CavePoca Roca CaveBray's CaveCatalan Bay CaveCave SHoly Boy's CaveDevil's Fall CaveGeorge's Bottom CaveLevant CavePete's Paradise CaveGreen's Lodge BatterySpider CaveHanover BatteryUpper All's Well CaveWest Place of ArmsWaterport CasematesBreakneck BatteryAlexandra Battery7th Rosia Batterycave entranceWellington Front Left BastionWellington Front Right BastionJones' BatteryPrincess Caroline's BatteryGrand CasematesParson's Lodge BatteryFlat BastionbunkerNapier of Magdala BatterybunkerBatteryBatteryBatteryBatteryBatteryFarringdon's Battery3rd Europa Advance BatteryOrange BastionJews' Cemetery BatteryMontagu BastionbunkerKing's BastionDevil's Tower EmplacementRock Gun BatterySouth BastionGBC Broadcasting HouseEngineer BatteryEuropa Advance Batteries 1st & 2ndGenista BatteryNorth Bastionfort / batterybunkerbunkerNorth Jumper's BastionbunkerPrincess Caroline's BatteryGrand CasematesParson's Lodge BatteryFlat BastionbunkerNapier of Magdala BatterybunkerBatteryBatteryBatteryBatteryBatteryFarringdon's Battery3rd Europa Advance BatteryOrange BastionJews' Cemetery BatteryMontagu BastionbunkerKing's BastionDevil's Tower EmplacementRock Gun BatterySouth BastionGBC Broadcasting HouseEngineer BatteryEuropa Advance Batteries 1st & 2ndGenista BatteryNorth Bastionfort / batterybunkerbunkerNorth Jumper's Bastionbunker
mapped road mapped tunnel cave entrance bunker fort / battery

Basemap tiles © OpenStreetMap contributors, served by openstreetmap.org. The dark and light modes need no network; only this one fetches anything.

The gap

11.0% of the tunnel system is in OSM
6.06 km mapped48.9 km not

The missing 48.9 km is not an error. It is classified, sealed, or both — the limit of what a public map can hold.

Two gaps, opposite directions

tunnels, published55.0 km
tunnels, in OSM6.06 km
public road, official29.0 km
public road, in OSM57.21 km

OSM holds 11.0% of the tunnels and 1.97× the official road length. Both are definitional, not sloppy: one counts what cannot be surveyed, the other counts service ways and both carriageways that no road statistic does.

Longest mapped tunnels

Admiralty tunnel957 mservice
Dudley Ward Way693 msecondary
Ragged Staff Magazine659 mservice
Keightley Way405 msecondary
Kingsway Tunnel360 mtrunk
Kingsway Tunnel352 mtrunk
Kingsway Tunnel285 mcycleway
(unnamed)123 mservice

Where the underground surfaces

  • 84 fort
  • 28 cave entrance
  • 27 bunker
  • 4 base
  • 4 range
  • 3 office

Recorded

  • Tunnelling ran 1782–99, 1933–38, 1939–45 and 1956–68.
  • Excavation peaked in 1942 at over 35,000 cubic yards; the spoil extended the airfield.
  • The Stay Behind Cave, cut in 1941–42 for six men to be sealed inside, stayed a rumour until 1997.

Network by class

service63.84 km
footway22.54 km
residential19.72 km
secondary12.30 km
pedestrian8.75 km
primary7.50 km
unclassified7.45 km
path7.24 km

Geometry © OpenStreetMap contributors (ODbL), measured from a locally hosted extract. Lengths are geodesic. The published tunnel total is 55.0 km and the official road total 29.0 km; both are sourced. Every historical claim on this page is cited in docs/sources.md. Generated by fwh_gibraltar.

Generated by Facetwork workflow gibraltar.HollowMountain · view FFL · source repo