Legend abounds in Edinburgh about a city beneath the streets, where people lived in ancient times, and which still exists to this day, forgotten by the world above. Like most good legends, there is an element of truth to this, an element that can still be seen.
Edinburgh Castle is built high on a craggy rock approachable from only one side, making it ideal for defence purposes, but not much good for building a city around. The geography was formed at the end of the ice-age as the glaciers receded and scraped away everything in their path except the tough basalt hill on which the castle is now built and the softer sandstone slope that stood behind it. It is on this narrow slope now called the Royal Mile on which the city first began to be built, but this left little room for expansion a problem further compounded by the construction of two city walls and a loch to protect the city and further hem it in.
To allow the city to expand, three bridges were built to join up with the surrounding hills, and it is in the vaults of these bridges that the underground city developed. Used as workshops and accommodation by the poor and as drinking dens by the rich (including the Hell-Fire Club) these vaults developed a life of their own. As the city built up around these bridges, these vaults vanished from view, but not from legend, and as you walk along the Cowgate, you can see a single 30ft archway of the South Bridge; another 19 archways still lie hidden behind the buildings to either side.
A number of different companies now offer tours of these vaults beneath the South Bridge. The most established are Mercat Tours (0131 225 6591) who run a variety of tours that include include visits to some of the bridge vaults. More salacious is Auld Reekie's Ultimate Ghost & Torture Tour (0131 473 3838) whose costumed guides use every shock tactic in the book and whose tour includes a working pagan temple and a visit to a small torture museum. My favourite is Hidden Historic Vaults (see TIC for details); it doesn't do ghost stories but visits the very lowest levels of the bridge vaults, and is by far the most authentic of the tours.
Auld Reekie tours offer a fun way to spend an hour away from the busy city streets above as good as any horror film while the Historic Vaults tour offers an insight into daily life at a fascinating time in this city's history, why not combine both tours for an afternoon's entertainment?