An encyclopedic collection of mammal penises.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

These fantastically named natural pools look like something out of a Scottish myth.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Iceland's largest lagoon is home to stunning multi-colored icebergs.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

The ancient tomb acts as a calendar that keeps perfect time.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

The world's longest known cave system.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

Welcome to old Florida, where a 1940s mermaid show is still enchanting visitors.

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

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

The atmospheric road was never meant to be so creepy.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

A mysterious castle built as a monument to lost love.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

The oldest cemetery in New Orleans, resting peacefully for over 200 years now.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

France's most famous cemetery, with some of its most curious tombs.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."