Rare recess caves fill this unbelievably beautiful Ohio park.

An unassuming secret door once led to a legendary watering hole.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

When ecosystems collide in the arid Southwest.

The beauty of urban decay, hiding some dark secrets.

One man's ambition created this psychedelic log home.

A castle built by an eccentric medieval enthusiast in rural Ohio.

Mysterious ancient boulder carved with petroglyphs in the mountains of Western North Carolina.

An extraordinary mixture of natural beauty and man-made phenomena.

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

The eccentric mansion of one the most popular horror authors of modern times.

An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

This lake in the Cascades lives up to its name, disappearing down a hole every spring.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

The longest navigable underground river in the United States is home to countless blind and albino animals.

This massive store is home to an eccentric collection of vintage, retro, and peculiar goods.

A colorful architectural gem in Seattle's uniquely modern Central Library.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

This Big Sur waterfall drops 80 feet directly into the Pacific Ocean, and inspired the hillside house up top.

Home to the infamous "Typhoid Mary" and the worst loss of life in New York's history prior to September 11, 2001.

European castle ruins in an American state park are actually the product of death and grief.

Hidden beneath a bridge, this waterfall is known for the large amounts of graffiti painted on its base.