Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

Perhaps the most spectacular grotto along the Algarve coastline.

The ship that got left behind.

A former reservoir that was only recently discovered after more than 60 years of disuse.

A once-booming Mississippi River town with a history of racial violence is now eerie and mostly abandoned.

The eerie remnants of an ancient forest were hidden under the sand for centuries.

Generations have refused to move this doll from its dusty resting place to preserve a castle from a watery fate.

Inside this old train depot resides a multi-line model train covering western North Carolina.

A huge musical instrument played by the ocean.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

This lighthouse was crafted as penitence for the theft of wine bound for a monastery.

One of the oldest seagoing boats in the world can be found at the Dover Museum.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

Described by William Wordsworth as a "World of Wonder."

An eerie, derelict amusement park in Berlin.

Designed as a labyrinth, this subterranean prison was crafted without bars or doors.

Inside this museum is an ongoing excavation of an ancient shipwreck.

A ship that lived many lives under many names is now known merely as the "Ghost Ship."

Once the most densely populated place in the world, this island is now a ghost town.

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

Abandoned businesses, homes, and rusted cars are all that remains of this stopover town.

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

These ruins have been linked to a sherbet factory that exploded, but the story may be entirely fictional.