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
9. Scotland Street Tunnel
The mile-long Scotland Street Tunnel once formed a rail link directly under the New Town between Waverley Station and Canonmills. It was abandoned in 1868 after just 21 years of operation and has been mostly closed off to the public ever since. Photo: Unknown