I've been catching up on some of the topics on these forums and have picked up on many mentions of our cave system. Because this subject arises under many other topics, I thought a new one would alert everyone at once to what I hope is a new "find". Apologies if this link has already been posted (I did a Forums search & I've not seen it in any topics that I've looked at).
It's a fascinating website, allowing a "fly through" of many of the cave systems under our great city.
http://nottinghamcavessurvey.org.uk/