An urban laboratory.

Originally conceived as part of a proposed Arizona State Capitol building in the 1950s, this structure built in 2004 stands as a monument to the architect's legacy.

A historic hydroelectric power plant serves as the unusual backdrop for a public park.

A mysterious "wedding cake" castle in the middle of the urban desert.

This collection of vintage signs reflects the long and colorful history of this Arizona town.

This rustic cabin, outfitted with gun slits, was once home to John D. Tewksbury, patriarch of the bloodiest family feud in American history.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

An abandoned facility that has become a place of ritualistic satanic worship, or so rumor has it.

This roadside attraction in the woods of Mississippi is a scalable replica of the Holy Lands during biblical times.

Built following the War of 1812, this fort has withstood hurricanes for centuries.

Once defending the city of New Orleans from invasion by sea, this fort faces an uncertain future.

Pirates had to be ousted from the land where this now ruined Louisiana fortress was built.

The crumbling ruins of this southern American fort have survived storms, war, and cults.

This abandoned Civil War fortress is slowly being swallowed by the waters of Lake Borgne.

This knobby, drooping New Orleans oak is a favorite place both for climbing and for meeting giraffes.

A swamp and garden tour featuring local wildlife and exotic botanical specimens from around the world.

Nestled in the heart of a Texas town is a dreamy secret garden dating back to the 1940s.

Hike the ruins of a zoo that was shut down by an unsolved murder.

Under a playground is a little-known sealed train tunnel that likely contains the bodies of workers trapped by cave-ins.

Heron, whitewater rapids, and urban industrialism all add to the beauty of this concrete nature walk.

Memorial stone for GWAR vocalist, depicted in his iconic costume.

Location of a reliquary containing bone fragments of 18 saints.

The site of Martin Luther King Jr.'s arrest as he attempted to have lunch.

Despite being burnt down multiple times, the ruins of this South Carolina church are still standing.