In this case a long-abandoned tunnel belonging to a coal mining company... abandoned so long, modern maps omit it entirely.

That's awesome!

Something similar to what my father found at Wet Earth Colliery, near St Helens in Lancashire, UK. A complete scheme of underground tunnels, an inverted 20-foot diameter syphon under the River Irwell, with different tailraces, weirs and other water control mechanisms that had been totally forgotten. There was also a large underground pumping station with sluice controlled waterwheels (or turbines depending on the period) used to pump water out of the Colliery. This was recently shown on Fred Dibnah's prog on BBC2 (alas, without credit to my Dad who found it with his partner Geoffrey Banks). Quite an amazing piece of industrial history - which at the time of it's creation was unique and hailed as a superb piece of engineering considered "of national importance", establishing the reputation of James Brindley as a skilled Civil Engineer.

Now it's not even marked on the map.

PS Do a Google search for "James Brindley" and "Wet Earth Colliery" and you turn up some interesting results. Have a look at this page for example.

Why do you suppose the link in your first post doesn't open up in a new window?

Uh, should it?

Now that stuff is cool Rob, not only because it's within walking distance from my house. I forgot you're from round here.

Hmm. If I try to edit the non-popup post, it shows the link as an "<a href>" link, not "[url]", whereas other posts are just "[url]"-style. I can't get any "<a href>" stuff to work. I don't know how it happened on his or why it's working.

BBS weirdness.

Actually, as a moderator, I can choose to use HTML in initial posts (but not replies -- weird). I wonder if that affected it in some way.

I did choose to use HTML when I posted it. That's probably why.

That explains it, then. The "[url]" thing automatically adds a "target="_blank"" attribute to the link, which opens it in a new page whereas Derrick didn't do that.

Ah, well that makes perfect sense then. It just turned me around for a second there. I closed the window after clicking on your link like I always do and the board was gone. For a second I was thinking 'did I click on an attachment link without knowing it that somehow took me to a web page?' since attachment links don't have a target in the link -- a behavior of the bbs that I've always found annoying/inconsistent.