One of Amsterdam's narrowest houses is located right across the canal from its widest.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

A curious collection dedicated to human and animal anatomy and pathology.

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

Just your average Marie Antoinette–themed speakeasy in an abandoned 19th-century subway tunnel.

An engineering error ensured this cavernous 350-foot-long subterranean thoroughfare was never used as intended.

Much of what constituted mid-century Liverpool now litters a beach outside of town.

The pretty iron lamp is a reminder of the architecture underneath London's streets.

The ghosts of Britain's telecommunication past sit rusting away in a small village in England.

Britain's tallest megalith towers over the cemetery of a quiet English village.

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

A terrific purveyor of natural history objects and curios.

Beer lovers thirsty for knowledge can now visit a museum devoted to the world's largest hop-growing region.

One of Edinburgh's oldest pubs hides a 19th-century skittles alley in the back.

A pair of stones embedded in an Edinburgh street memorialize one of the city's last public hangings.

The world’s first dedicated cloud observation platform.

Two ancient Buddhist temples crown this dramatic rocky pinnacle.

At the right time of day, sunlight floods through the roof of this cave and illuminates the small pavilion hidden within.

The remains of an abandoned dinosaur theme park litter the woods just off the highway.

One of the largest ochre quarries in the world, hidden in a limestone landscape.

One of the longest wooden benches in the world snakes around Geneva's Treille Promenade.

A suspended footbridge allows for traversing this gorge carved through the French Alps.

This retro underwater observation tower would make the perfect lair for a sea-loving villain.

An icy lake tucked among jaw-dropping alpine panoramas.