What motivates humankind to burrow deep into the Earth?

Urban camping means different things to different people, from living without a vehicle or electricity and plumbing to squatting in unused properties and more.

Here are some extreme city sports you aren't likely to see in a sports stadium.

These street art images and biographies merely scratch the surface and begin to convey their amazing artistic talents though sample artworks and street chalk drawings.

Fortunately, with these tips, urban exploration can be a legitimate hobby without the risks of illegal building infiltration.

More and more designers are developing nomadic alternatives to traditional models of static urban living.

The ability to hide plain site can be a real advantage when exploring urban abandonments.

Some have even caused scientists to question the history of human civilization.

What if you saw the building walls and other urban obstacles around you not as barriers, but as tempting challenges?

An MIT SENSEable City Laboratory project, Wiki City Rome seeks to create a "Real Time Rome" from various data sources.

Architectural light graffiti, or projection bombing, falls somewhere curiously in between.

Here are some great urban exploration photo collections and other links related to building infiltration and draining.

What is urban life without a little excitement, spontaneity and strangeness?

Surprisingly, neither is the art of constructing tall buildings, as evidenced by the city of Shibam.