There used to be — and I hope there still is — a website called something like "Dread Portals". It contained many photo of those ominous doorways that litter our urban world: old, disused, broken-looking, but firmly shut; under railway arches, down dark alleys, half-hidden by hedges, etc. For each doorway, the site had a brief explanation of which hell it led to and a potted history of which demons had used it and why.
It's a bugger trying to use Google to find it. Try searching for variations of "doors gateways demons hell" and you find an awful lot of stuff that isn't what I'm looking for. If anyone knows the site of which I speak, please please tell me where it is.
Thank you very much.