Dark Places
Dark Places is a trusted and active forum and research portal relating to urban and underground exploration.
The site is run by the hamster loving explorer, Root and has a huge collection of posts, photographs and a wiki.
More information
Visit Dark Places - Darkplaces is an independent meeting point for all underground related explorers to chat, meet and share information.
Root's explorer profile - Root is interested in bunkers, caves, Cold War sites, military bases, mines, pill boxes, potholing, quarries, ROC posts, tunnels and World War II sites.