Below are a number of links to similar sites and other places of interest on the internet:

Infiltration
“Infiltration offers a mix of the practice and theory of urban exploration in areas not designed for public usage. This site is the online companion of the paper zine about going places you’re not supposed to go.” – It has a great links section by country

Cave Clan
Melbourne Cave Clan site

Urb-ex
Urban Exploration in Belgium

Dark Passage
A page devoted to run-down structures in New York

zahkunst.net
Photographs of abandoned warehouses</font>