The Denny Substation has been called "the coolest substation in the world" and sits in a densely populated Seattle neighborhood.

A church filled with the bones of hundreds of virgins martyrs—or so they say.

The final resting place for a wealthy Roman family, this tomb might be the best preserved of its kind outside Italy.

How did a lighthouse wind up in the middle of this landlocked German city?

This small condiment museum makes all manner of mustards with a 200-year-old mill.

All that remains of this small town is its mass grave and a myth of a voodoo priestess who predicted its demise.

This Roman relic was discovered in Scotland by a mudlarking ferryman.

Every birth, death, and marriage is recorded in these color-coded leather-bound books.

This lava formation earned its whimsical name from the log-like formation of it stones.

This large, castle-like structure is hidden amid the mountains on the grounds of the Utah State Hospital.

This ultra-modern California span is actually a titanic solar clock in disguise built by famed architect Santiago Calatrava.

A collection of huge, site-specific sculptures sitting in the Montana woods.

A lighthouse built to save lives that took quite a few with its treacherous location.

The haunting ruins of Jack London's dream house.

California's own majestic geyser is powered by a subterranean volcano.

The restored and active Victorian-era final resting place of San Francisco.

One of just a few cities in the world to base their center of government on an island. Others: Paris and Osaka.

Remnants of a quarry company town still stand on the banks of the Wapsipinicon River.

A pop-culture attraction outside of Dyersville, Iowa, hits a home run.

A hidden oasis in the heart of Minneapolis is also an Important Bird Area.

The highest point in Iowa, while not that impressive to mountain states, has earned its own monuments.

A riverside park built around the ruins of a massive dam that collapsed in 1909.

A roadside collection of over-sized iron creations that are a bit more macabre than most.

One devoted couple has donated multiple recreations of Michelangelo's sculptures to this South Dakota town.