Martin Bricelj Baraga's monolithic sculpture measures the blueness of the sky, and changes color to match it.

A miniature train-ride through Slovenia's largest cave system.

This one-time health resort was used by aristocrats around the world.

This massive subterranean fissure is known as the "underground Grand Canyon."

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

See six states, pickled freaks, rocks, and antiques.

A Rocky Mountain city provides a happy ending for a pinto pony and his Brobdingnagian red chair.

Overlooking the Colorado Convention Center is this giant sculpture made from thousands of triangles.

Neal Cassady may still have an open tab at one of Denver's oldest watering holes.

While comics are the main attraction at this megastore, the second floor plays host to an exhibit fit for a museum.

The oldest operating cemetery in Denver is the eternal home of some of the Centennial State's most famous residents.

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

A downtown park built on top of unclaimed graves.

This museum offers an actual time machine back through Colorado's past.

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

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