h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Bit disappointing not to have any reference to that. Two reasons for the rather unsanitary conditions prior to the construction of the New Town were the loch and the population density (city growth was constrained by a series of city walls and the loch itself). This gave rise to a vertical city where people literally lived one above the other. Gradually, parts became totally built over to the extent that there are whole closes which are now cut off from the outside world. Not to mention the cellars under the bridges.

I've been down there - very, very eerie indeed. Some scary stuff happened down in them there vaults, as they're also known.

Vaults, vaults. That was the word I was looking for!