Europe's official "zero-level," the equator of elevation.

The world's oldest Jewish library was founded by Sephardic Jews in 17th century Amsterdam.

This pirate-broadcasting-tower-turned-restaurant played a rebellious role in the history of Dutch television.

The Bauhaus-style former industrial complex is considered the world's most beautiful coal mine.

At the base of this tower, a plaque marks the original center point of the Netherlands.

A ruined castle stands atop a hill surrounded by dragon lore.

A memorial for a young woman and her ghost, which are claimed to have caused countless deathly shipwrecks.

Centuries of warfare, tragedy, executions, and poetry come together in this 13th-century fortress.

Tiny castle in the middle of the Rhine made you pay to pass.

Legendary site where an evil bishop was devoured by rodents.

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.

A tower-like theater in the Swiss Alps built to withstand the high winds and avalanches of the mountain pass.

The remains of St. Lucius of Chur were said to be kept in this crypt for several centuries.

The great Danube river starts here.

Rich with fauna and flora, nature-lovers can walk across the sea at this UNESCO World Heritage spot.

Live out your childhood construction fantasies in this one-of-a-kind gyrating hotel.

A unique form of erosion created an uncanny landscape of boulders perched atop slender columns of clay.

A family accused of witchcraft once called this medieval tower home.

This work of engineering is imbued with elegance and ingeniousness.

Gladiators once walked this ancient, subterranean passage.

This former mill comes to life during the Christmas season.

What appears to be an ancient Roman temple is actually a Catholic church.

The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.