That people had lived there was only discovered in 1985 during an excavation, when middens were found containing toys, medicine bottles, plates, and other signs of human habitation.
The South Bridge, built to span the Cowgate gorge between High Street and the growing University of Edinburgh on the Southside, was first proposed in 1775, although work did not begin until August 1785.
The remaining eighteen arches were enclosed behind tenement buildings built to allow the area to serve as a commercial district.
The vaults were lighted with fish oil lamps, which combined with the stench of stale waste and chamber pots made the area barely habitable.
[3] There is no evidence that Burke and Hare, the infamous serial killers who sold corpses to medical schools, used the vaults for their body snatching activities.
[4] On Saturday 1 July 1815, the Edinburgh Evening Courant reported that: It is not known when the vaults complex was closed down, with some suggesting as early as c. 1835 and others as late as c. 1875.
Hundreds of tonnes of rubble were removed by hand and several interesting artifacts were discovered including thousands of oyster shells.
There are areas within The Caves that are the building remains of what was Adam Square, that were demolished to make way for the erection of the South Bridge.
The original terracotta floor tiles, a hearth stone, and what remains of a fireplace, were found in one of the rooms within The Caves whilst it was being excavated.
The voices continued to be heard on the recording for some 20 minutes before abruptly ceasing after what appears to be the sound of children yelling.