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

These azure waters were thought to lead to the Mayan Underworld.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

Fortified medieval tower house with lovely roof garden.

This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

A fearsome dragon clings to a corner of Munich's city hall.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

Home to more than 13,000 pieces of war memorabilia and military equipment.

Secret North Korean passage discovered below the world's most dangerous border.

South Korea's largely symbolic, barely used gateway to the North.

One of the greatest heroes of the Titanic tragedy came from humble beginnings to this beautiful home.

This hot dog-shaped diner has moved all around Colorado, never been to New York.

Each year, teams of the world's best snow sculptors have 65 hours to create frozen masterpieces.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

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

The world's largest key collection features keys to the White House, Frankenstein's castle, and Hitler's bunker.

The spot in the Mile-High City that's exactly 5,280 feet above sea level (at least for now).

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

Explore some of the most unique vehicles in history along with a cast of unsettling mannequins.

A small horde of mythical creatures lurk almost imperceptibly within the museum's wildlife dioramas.

When ecosystems collide in the arid Southwest.

Home of the International Space Hall of Fame.

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