While some have become famous tourist destinations, others have been long forgotten and left uninhabited for decades.

. Gilmerton Cove
Drum Street in Gilmerton is home to the ‘subterranean chambers of a remarkable cave’ thought to have been inhabited up to 300 years ago. Situated around ten feet below the surface, the Cove consists of a 40-feet long passage with an unusual series of rooms and passages on each side. It became a tourist attraction in 2003. Photo: Phil Wilkinson

. Crawley Tunnel
Built around 1821, the little-known Crawley Tunnel is actually an aqueduct that transported water from Glencorse Reservoir. It runs for about a mile from The Meadows to the Grassmarket and The Mound where it meets Princes Street. Photo: Photographer: Scott Louden

. South Bridge Vaults
When the city's South Bridge was built in the 1780s, the architects incorporated a series of vaults into its 19 arches. Hidden from view beneath the bridge and hemmed in by buildings, the spooky vaults, which were at one time used to house taverns, cobblers and even a distillery, were eventually abandoned due to the lack of light and sanitation. Photo: Greg Macvean


6. Waverley Vaults
The vast ad labyrinthine Waverley vaults were built during the redevelopment of Waverley Station by the North British Railway Company in the mid-1890s. Previously used for storage by nearby traders at Market Street, the vaults, which effectively support a large section of Waverley Station, now lie mostly empty and unused. Photo: Colin Hattersley

7. Barnton Quarry nuclear bunker
Buried 100 feet beneath Corstorphine Hill lies a chilling remnant of the Cold War: a secret bunker equipped to house hundreds of state and military officials in the event of nuclear fallout. The 1950s-built bunker, one of the only surviving types in the UK, was used to receive intelligence from radar stations across Scotland. Photo: Ian Georgeson

8. Alnwickhill Waterworks
Situated below homes at Liberton Gardens and Alnwickhill Road, the giant brick-built storage tank at Alnwickhill Waterworks dates back to 1875. Covering a space around half the size of Charlotte Square, the 15-million gallon tank once stored the city's water. Photo: Contributed