17th century streets hidden under Edinburgh were once a breeding ground for the black death.

Enormous lake at the bottom of a unique cave system.

A technicolor place of worship for Elevationists.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

Giant busts of 42 U.S. presidents are sitting in a field in Virginia.

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

The only swimming pool listed on the National Register of Historic Places is emptied and refilled each day with naturally filtered water.

This whimsical Oz-themed park had a wonderful impact on the surrounding neighborhood.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

A giant Troll lurks under one of Seattle's oldest bridges.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

A bizarre house filled with an astounding array of collections.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

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

On Japan's Tashirojima Island, cats are king.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

Dramatic river bend surrounds a natural red-rocked pedestal.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.