The most impressive of Basel's three remaining city gates.

Model Trains and Much More in Hamburg.

These ruins of a Soviet children's railway station have a haunted atmosphere.

This little medieval church hidden in the center of Yerevan was lost and rediscovered—twice.

Marvel at this immense work of art that greets arrivals to the city.

This enchanting green space houses a labyrinth lined with toxic plants.

Made up of 3,200 recycled glass bottles, this tree pays homage to Asturia's love of cider.

Eighty million natural history specimens call this gargantuan museum home.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

France's most famous cemetery, with some of its most curious tombs.

Hidden masterpieces in a small church in the medieval city of Bergamo.

This house certainly has a unique decor.

Naturally formed rock city in Poland.

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

The world’s narrowest house makes for an awkward, four-foot-wide living space.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

Real bones which are said to have belonged to a Polish dragon.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

An underground city of salt.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

The largest known Ancient Egyptian obelisk.

One of its engravings is believed to be among the first representations of medical and surgical instruments.