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

Extraordinary rock formations in open Peruvian fields.

This massive store is home to an eccentric collection of vintage, retro, and peculiar goods.

A waterfall 600 ft. inside a mountain, once the bane of gold miners, is now a spectacle of nature.

The first declared National Monument in the United States.

The corpse bride of Portugal.

A stunning bridge that appears as if it's lunging to the shore, and has a legend of a devilish architect.

Sloth rehabilitation center in the jungle of Costa Rica.

This Italian church is as beautiful as it is common, except for the real skulls decorating the many mannequins inside.

An ancient city exhumed from the depths of the ocean.

A musical composition 1000 years in length plays at the Trinity Buoy Wharf in London.

Appropriation-friendly collection of books, periodicals, and more.

The Last Home of an Executed King.

Sacred Buddhist home of some spiritual monkeys.

Once thought to be the oldest living tree in the world, Methuselah was germinated before the Egyptian pyramids were built.

The world's smallest movie theater runs on solar power—an attraction in itself.

Now a pile of ruins and rubble, this was a lovely mountain town as recently as 1960.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

This immaculate and historic water garden culminates in a massive stone dining table with an inset fountain for chilling the wine of the Cardinal's guests.

White llama terraces dazzle in Peru's "other Machu Picchu."

Death rituals and sacrifice inside a Peruvian megalith.

Slaughterhouse Five opens its dank doors to fans of Kurt Vonnegut.

Is it an island or a volcano? That question probably explains why it's uninhabited.

A volcanic landmark located on an Ice age lake bed.