Building Men of War and Indiamen from Holland's Golden Age.

One of the most important yet well-hidden museums dedicated to the history of medicine.

Breathtaking and huge 430 year old maps of Italy.

This subterranean shrine beneath a bike rental store celebrates the iconic Italian scooter.

A fairy tale castle in modern Rome.

Inside this McDonald's you can dine on your Big Mac and fries next to a 2,500-year-old Roman wall.

This ancient market is often referred to as the oldest shopping mall in the world.

Ever hear of the Milazzo Cage?

The final resting place of the poets Shelley and Keats.

Gods clash with machines in a power plant regenerated as a museum.

Repurposed space and ultra-modern construction collide to create this geometric wooden spectacle.

Lombardy poplars planted to imitate the size and shape of the Cathedral of Notre-Dame de Reims.

Various sculptures are a rotating exhibit in this small town.

One room inside this building mesmerizes all with its parabolic dome.

The only remaining U-boat that is still floating never actually saw any action in World War II.

A German artist built a home and garden filled with whimsical art pieces, like a massive, operational volcano.

A radio telescope for listening to the stars, based in one of the cloudiest countries in the world.

This imposing tower named after the mythical sword of King Arthur is considered the tallest freestanding climbing wall in the world.

Hop aboard a charming bog train to explore this rare open-air museum of peat.

This giant radio telescope would be a rusting ruin if it hadn't become such a beloved relic.

One of the oldest wine cellars in Germany is now a restaurant beneath Bremen's town hall.

Böttcherstraße's bells, extolling Nordic virtues and the great conquerors of the world.

Constructed by forced laborers, this submarine pen is now a museum and war memorial.

There are two dozen tanks just sitting in an open field in Lower Saxony.