A fantastic castle rumored to be the birthplace of King Arthur.

This exemplar of modernist architecture is meant to captivate and inspire students of the Cooper Union.

The final resting place and once home of the Bandit Queen of the West.

The site of one of history's most indelible and horrific tragedies.

This innocent-looking townhome is actually a subway exit.

A historic covered bridge, only one of two remaining in North Carolina.

The former sign of this immortal music venue is just that--undying.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

This impressive tunnel was dug entirely by hand over the course of 36 years.

A recreation of the doomed ocean liner in the middle of the Smoky Mountains.

A world-class observatory in the California desert.

A Barbary Coast watering hole built into a Gold Rush shipwreck.

One man’s hobby is another man’s world of metal wonders.

Civil War-era Fort designed to withstand invasion and attack, with tricky traps called "murder holes."

A modest reminder of treacherous waters at the Golden Gate.

Abandoned bridge hidden deep in the San Gabriel Mountains.

Dive bar built out of the remains of a whaling ship.

Collective dedicated to restoring steam engines.

Mount Nyiragongo has erupted at least 34 times since 1882 and is home to the world's largest lava lake.

A time-capsule monument reminding future generations of the importance of efficient and effective use of natural resources.

A flamboyantly decorated bridge signals diversity and fellowship at the entry to Indianapolis' Broad Ripple Village.

Statue in Salem of the woman who starred as the witch Samantha in the sitcom "Bewitched."

The ghost town that was one of New Hampshire's first settlements now exists as a park detailing its history.

The graves of a Connecticut family thought to have been plagued by a vampire.