Series of storm drains connected to a dark urban legend.

A lone tower rises above the cliffs in a city park, offering fantastic views of the Connecticut landscape.

This evocatively named natural crevasse was created by a torrent of water that smashed right through a granite deposit.

This enormous abandoned factory is now a makeshift graffiti gallery.

An overgrown and abandoned tuberculosis ward resides in the midst of a quaint modern neighborhood.

The ruins of an abandoned 18th-century town that is slowly being reclaimed by the forest.

Now home to hardy plants, these sand and gravel dunes once held back a massive prehistoric lake.

The ancient past meets the retro-future at these dinosaur tracks that are protected by a geodesic dome.

This historic park site contains the last remnants of a once bustling canal system.

Inside a state forest, the forgotten remains of a Cold War defensive installation.

This old cement mine has been used as everything from a mushroom farm to a recording studio.

This stone gatehouse was once the entrance to a historic mountain resort, and it had a cameo in a cheesy cult horror movie.

This huge, disused viaduct is now a crumbling concrete underworld of covered in years of graffiti.

Once the world's largest reinforced concrete structure, this abandoned bridge now beckons urban explorers.

This Boy Scout retreat acted as "Friday the 13th"'s original Camp Crystal Lake.

One of the U.S. Forest Service's only mansions is outfitted with a dinner table for floating food.

The remains of a community that was forced to move for a dam that never materialized still rot in this Pennsylvania park.

This abandoned asylum was once a state of the art facility before devolving into one of the most deadly mental institutions in American history.

The well-preserved remnants of a bridge that once made up a WW1-era military railroad.

This homestead was occupied by Union soldiers, who believed the owners were signaling Confederate forces.

These beautiful ruins deep in the Pennsylvania woods are thought to have been a ski lodge or a speakeasy, but no one really knows.

A wonderland of caves in eastern Iowa.

This South Carolina water tower is an icon of the city of Walterboro, but it also once served as the county jail.

"Not too many people can say they've had a nuclear bomb dropped on them, not too many would want to." — Walter Gregg.