Historic medieval fortified city in southwest France.

In this medieval church, a centuries-old stuffed crocodile hangs from the ceiling.

Partially collapsed lava tube and cave system complete with concert hall, underground pond, and unique albino crabs.

Visit a surreal landscape so otherworldly NASA actually used it to train the Apollo 17 crew.

The chefs at El Diablo use heat generated by an active volcano to cook the food.

This beautifully verdant lagoon is tucked below a massive volcano in a crater atop a black pebble beach.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

Rumors and legends of secret Nazi activities surround this eerily remote island mansion.

The first declared National Monument in the United States.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

An architect's childhood fantasy treehouse made real.

Visitors to this library are in for a real-world education in modernist architecture.

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

A monument celebrating the idea of reaching inaccessible places.

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

Rome’s legendary peephole vista is also a former Crusader stronghold.

The smallest post office in the United States is no bigger than a broom closet.