An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

This dizzying span over the ancient Algerian city was once the highest suspension bridge in the world.

Now home to a drinking establishment, this building has a macabre history.

Famed for its pie, this eatery has a hidden tunnel that allowed Catholics to secretly walk to church during the Reformation.

Amsterdam's narrowest house facade is a monument to 17th-century tax evasion.

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

A floating cat sanctuary on an Amsterdam canal.

Inside this medieval church resides a unique set of murals.

World's strongest whirlpool.

The man who helped establish the first rules of golf.

This tablet indicates where the tragic monarch returned to begin her tumultuous downfall.

This lesser-known leaning tower is all that remains of the medieval castle of Vernazzano.

A sinkhole and now a swimming hole, too, full of dazzling turquoise water.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

Islanders once used this dramatic, otherworldly landscape to hide their cattle from Viking raiders.

Strange rock formations tower above the river that snakes through this enchanting Icelandic canyon.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

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

Amsterdam's former hotspot for public executions and dissections.

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

The former headquarters of history's oldest megacorporation.

A public urinal so pretty, it was declared a national monument.

How did a French journalist’s grave become the sexiest statue in the cemetery?

The final resting place of the "father of special effects."