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.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

A floating cat sanctuary on an Amsterdam canal.

Museum preserving torture methods from the past.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

The world's only museum devoted to the wonders of fluorescence.

Shimmering sea-colored mosaics and Jesus statues cover this opulent building.

A subterranean display of public art and architecture.

This unique bridge curls up like a caterpillar to let boats pass and then unfurls again to span a small canal.

This tiny little pool is said to be home to a malicious mermaid named Jenny Greenteeth.

A beautiful ruin of a 14th-century Plantagenet castle built by a medieval mercenary.

At this unusual park, domes, ladders, chairs, and more are made from trees.

An ancient pagan site swirling with legends in the foothills of Franconian Switzerland.

A towering monument to war, located on a beautifully peaceful hill.

The last remnants of a massive medieval wall that once encompassed the city of Berlin.

An engineering wonder at Pillnitz Castle protects a precious 230-year-old flowering shrub.

An abandoned underground bathroom is now a space for public art.

Originally envisioned by King Ludwig II to rival Versailles, Herrenchiemsee's "New Palace" remains half-gilded for lack of funds.

It's good luck to be mocked by this monkey.

The first (but not only) upside-down house in Germany.

This historic little railroad runs through some of the most beautiful scenery in Germany.

This former Nazi castle was built as a school to train what would have been the future of the Third Reich.