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

Mysterious stone tower featured in many alternative histories of the New World.

Maryland's first (and last standing) toll house on America's first federal road established the state as the "Gateway to the West."

A small brick parlor house and artist's studio located in the wilderness is surrounded by imposing suburban palaces.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

This former Cold War missile control site played an important role in the creation of GPS.

This suburban house is made of dirt, and almost sparked a revolution in home construction.

This massive swimming pool is the high tech home to the human-powered submarine races.

This sprawling farm was once a Cold War-era hideaway for the nation's top diplomats.

A former special storage facility for documents during the Cold War.

Three abandoned missile silos are hiding in plain sight behind a suburban development in Maryland.

Proto-CIA agents trained with grenades in the sand traps and fired machine guns from the fairways.

Was there a small "backpack nuke" hidden in the attic? JFK apparently thought so.

A cenote sitting in the middle of a parking lot shows the Yucatán Peninsula at its most urbanized.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

Abandoned Coast Artillery fort now serves as graffiti canvas and sightseeing vantage point.

A hacienda that features all things uniquely Yucatán.

One of the few places where you can visit a cenote and Maya ruins at the same time.

The oldest still-operating tavern in the United States was once owned by a pirate.

The first newspaper printed by an expeditionary force was published in this colonial mansion.

The location where the American Revolution ended.

The first marker along the famous boundary.

It's said that this stone with its mysterious runic inscription is evidence of the Norse visiting Narragansett.

Rumors of the occult haunt this upscale 1920s hotel.