The place to find out what is lurking beneath the city streets.

A resource fund devoted to photography, architecture, industrial archaeology and urban exploration realized in close collaboration with ZoneTour.org.

Petr Kazil's page on urban art and exploration in Rotterdam and beyond.

Photos and brief descriptions of various interesting subterranean sites in Estonia.

Although more academic than adventurous, this site offers a collection of maps, pictures and snippets of trivia useful to those seeking military leftovers in Germany.

Modern ruins in Finland. Photographic tours of abandoned factories, tunnels and bridges.

Italian abandoned places. Mostly factories: textile, steelworks, brickworks, automobile plant, cotton mill.

Two guys from Finland visiting places that are no longer actively used.

Remnants of a medieval water system under the town of Plzen, Czech Republic.

Bunkers, tunnels, cannons, manholes, castles, arsenals, aerials... near La Coruna, the northwest coast of Spain.