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

This fast-food outlet is the only space and UFO-themed McDonalds in the world.

A museum dedicated to the alleged Roswell Incident.

This is one really big nut.

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

A sprawling collection of over 106,000 toys from around the world.

This southwest-styled home in Santa Fe claims to be the oldest house in America thanks to an ancient bit of foundation.

A sharp bend in a dramatic river canyon cut through red rocks.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

Every equinox this Maya pyramid puts on a spooky ancient light show.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

If you can look past the nearby sewer pipes, this urban sinkhole grotto is a mini-paradise.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

In the midst of a living monument to Soviet social engineering, Polish Catholics built this church by hand.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

The interior of the Overlook Hotel in "The Shining" was based on this Yosemite original.

A giant scale model giving a sneak peek at what urban planners see for Shanghai by 2020.

The name of this ancient Indonesian temple translates as "Elephant Cave" but it could be more accurately called "The Hellmouth."

Hindu temple of the dead home to hundreds of long-tailed macaques.

This stunning concert hall has become a symbol of Iceland's national recovery.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

Singapore's landscaping project is home to 18 incredible Supertrees.

Artifacts and memories from the Vietnam war, located in a place that experienced it first hand.