Macabre astrological automaton clock dating to the late 1400s.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

The anatomical-pathological collection of a man who changed surgery.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The most visited, and possibly most controversial, museum in Germany.

The most famous location in China was home to whole dynasties worth of imperial rulers.

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

A beautiful but toxic fountain of mercury.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

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

The world's most active stratovolcano is almost always erupting.

Stalactites and stalagmites in a beautifully lit cave.

The titular "little arch" near this Italian resort is one of the most popular diving spots in the country.

On the coast of Sardinia, a once-great mining village is finding new life as a coastal resort town.

This one-of-a-kind archeological site is home to strange prehistoric ruins, the original use of which is still a mystery.

Devious political maneuvering and four ancient, working telescopes are central to the world's second-oldest observatory.

A 'living museum' in Leiden, the oldest of its kind in the Netherlands.