Walk 2,300 feet above the ground on the "Troll's Tongue."

A thin pane of glass keeps visitors from sliding off this futuristic skywalk.

Longest road tunnel in the world features an air treatment plant and the illusion of daylight.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

Take a walk in a recreation of ancient Rome.

This fairy tale forest hides scenes from some of the more obscure and bizarre Western nursery stories.

A miniature city, once ruled by the Queen of the Netherlands.

This unattributed sculpture in Amsterdam is hiding in plain sight.

The former home of a mad diplomat is said to still be marked in bloody, arcane scrawls.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

A beautifully eclectic mix of architectural styles.

An elaborate Mayan city shrouded in alien conspiracy revealed the tomb of Pacal the Great.

The meteor that sealed the fate of the dinosaurs landed at this site, one of the largest impact craters in the world.

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

Northern Ireland's Brobdingnagian stepping stones.

The lake that fills and empties itself at random.

This ancient Irish religious site is covered in ancient carvings, many of which have barely aged.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.

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