urban explorers

from the clip" Chernobyl and Pripyat ghost town"

from http://www.urbanexplorers.net/
The Urban Explorers Network is a social networking site for fellow explorers to find and share information about the built landscapes around us. Wherever you feel most at home, if you have the urge to see where most are blind, this is the website for you.
Urban exploring is definitely not for everyone, but for those who have experienced the thrill of exploring the abandoned, the decayed, the forgotten, there is no greater adventure.
What is an urban explorer? A person who explores restricted urban areas such as abandonments, tunnels, roofs, construction sites, etc.
Sound like fun? Then join the Urban Explorers Network and experience a whole new way of looking at your world.

see Chernobyl ghost town's clip
http://www.urbanexplorers.net/ghost-towns/chernobyl-and-pripyat-ghost-town.html

see also the clips of many others urban explorations 
http://www.urbanexplorers.net/explorations/