A floundering Polish shipyard was once the soul of the Solidarity movement that capsized communism.

A merchant court dedicated to the fictitious King Arthur is heavily adorned with bizarre Renaissance art.

These rare statues are one of the few remaining material witnesses to Old Prussian culture.

This 13th century Gothic brick castle is the largest in the world by surface area.

This antique thermometer honors the creator of the first universal temperature scale.

A huge wooden clock that is so beautiful its creator was forcibly blinded.

Several 12th-century ruins can be found inside this historical market.

Traditional 11th-century outdoor tannery.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

The courtyard of this small Marinid madrasa is a dazzling example of intricate Islamic architecture.

The other side is actually green.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

5,000 skulls in memorial to those killed by the Khmer Rouge.

There has been an astronomical clock on this spot since the 14th century.

Explore this medieval cathedral by trying to spot all the malevolent monsters hiding in its beautifully colored windows.

Visitors dating back to the 1600s carved their marks in the stones of the iconic tower.

Martin Bricelj Baraga's monolithic sculpture measures the blueness of the sky, and changes color to match it.

This 135-year-old weather station studied the effects of the climate on human health.

The Renaissance-era courthouse is a relic from the fortified town's centuries of Venetian rule.

Croatia's towering concrete blossom grows from the site of a World War II concentration camp.

Longest fortress system anywhere in Europe.

This picturesque medieval monastery guards a small trove of historic treasures.

Large, airy hallways hide within an impenetrable fortress that beckons urban explorers.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.