The abandoned train depot now doubles as a well-placed rest stop for those who take the road less traveled.

Before it was abandoned and left to rust alongside the road, this riverboat starred in a John Wayne movie.

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

Enchanting gardens surround a derelict mansion, all hidden in plain sight behind a stone wall.

This deserted Gold Rush town is home to a Masonic lodge that, strangely enough, still holds meetings.

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

Portland had a unique approach to Cold War-era protections.

These recently uncovered walls are all that's left of Washington, D.C's first defense contractor.

This forgotten boat elevator was an engineering marvel in its heyday.

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

An abandoned railroad tunnel forgotten by time awaits inquisitive hikers.

Ship skeletons haunt Baltimore's waterways.

An Industrial Revolution-era public work that purified water using nothing but sand.

An abandoned boat that's been stranded mysteriously for decades.

During WWII the U.S. Navy conducted primitive drone strikes on this Lake Michigan lighthouse.

A remarkable time capsule of American manufacturing deep in Maryland coal country.

These abandoned waterworks are crumbling into the Potomac River.

The remains of a century-old mansion that met a fiery demise years after it was deserted.

One of the world's largest automobile junkyards is a unique landscape of metal and moss.

Ruins of the elaborate house where the enigmatic costume designer threw glamorous parties for New York's theatrical elite.

The abandoned bathhouse is all that remains of the hot springs considered Florida's original tourist attraction.

This remote island in Iowa was abandoned after being devastated by flood.

In the woods of New Jersey lie the ruins of a munitions village abandoned after World War I and the remnants of a 1920s wooden racetrack.

One of the largest-ever mental hospitals now sits abandoned, surrounded by 25,000 unmarked graves.