An abandoned network of military bunkers and tunnels open for anyone willing to descend into the darkness.

The NBA player's elaborate former home is now a ghost of its old glory.

There is beauty and history in the ruins of this former company town.

A former hospital is now home to a pizza parlor and maybe a few ghosts.

Hidden deep within New Jersey Pine Barrens is a massive graffiti wonderland.

An abandoned observatory in the middle of the Illinois prairie.

Built by an accountant with a dream of running a grand resort, this estate has sat vacant for over half a century.

The only thing still moving in this town is the eponymous hot spring.

The once-abandoned 140-year-old hotel used in the movie "In Dreams."

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

An abandoned aircraft sits submerged in a lake in the Alaska wilderness.

An abandoned 19th century quarry in the middle of the woods, remade by unnamed wanderers into a massive series of rock thrones.

The concrete shell of an industry giant remains as a playground for graffiti artists, auto scrappers, and paintball warriors.

A theater sits abandoned on Roosevelt Road, once majestic in splendor, now majestic in decay.

This mountaintop beacon is only lit three times a year but shines like some kind of all-seeing eye.

This abandoned seaside fortress is now simply an imposing ruin being taken back by nature.

Unlike other abandoned asylums this empty institution welcomes visitors, just don't go in the buildings.

This forlorn park is the result of a failed investment turned tax dodge.

Bad farming practices caused this unnatural natural wonder.

Collection of trolley cars in the woods represent one man's attempt to preserve transportation history.

This airfield is home to a number of retired vintage planes in various states of disrepair.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

See just what life was like in a 19th-century prospecting town.

The tragic reality of a town riddled with rumors of haunts, chemical spills, and serial killers.