Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

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.

Once a mortuary that held the remains of Buffalo Bill, this Denver hotspot is now a death-fixated restaurant.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.

The final resting place of the great navigator, or maybe his brother.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

A lush indoor jungle fills this bustling Madrid transportation hub.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

Mountain where Jesus was first tempted by the Devil.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

The modern birthplace of Irish freedom.

A hugely vast Irish landscape of barren rock that stretches for miles.

One of Ireland's most infamous prisons for rebels including men, women and children.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

L.A.'s oldest operating bowling alley is a beautifully restored homage to its speakeasy days.

The programmatic glory of LA's giant whiskey barrel building has become an upscale reminder of the city's kitschy roadside past.

Historic funicular railway, believed to be the shortest railroad in the world.

Scores of vintage street lamps shine along L.A.’s Miracle Mile.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

Established in the '60s, a family-owned tropical drink bar founded by Ray Buhen, bartender to the stars.

America's most famous piece of self-built architecture.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.