A striking glass tribute to two sisters who suffered during Scotland's "Killing Time."

Madrid's last horchata kiosk is a blue-and-white beacon of refreshment.

The gigantic skull of a long-extinct species that once roamed the forests of England and Ireland.

The canine-themed book collection claims to be Europe's largest dog library.

A wonderfully eclectic Victorian aquarium lies in the basement of the Horniman Museum.

Art Deco and “Wrenaissance” mash-up, this recently restored royal residence has been home to kings and comes with secret monkey passages included.

This landmark church concealed a crypt packed with bones that was discovered thanks to the London Blitz.

A collection of comics, graphic novels, animation and caricatures devoted to exploring this often overlooked art form.

The final resting place to 300 Victorian-era pets hides inside the city park.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

Legend has it thieves once stashed their treasures in this crater in the Mexican desert.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Copenhagen's celebrated theme park and gardens.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

This Funeral Hearse Museum represents the finest in cadaver transportation.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

A beer pipeline runs beneath Bruges.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

This large copper bolt represents the benchmark for measuring sea levels in most of Europe.

This subterranean studio is filled with fascinating kinetic art.

Amsterdam's former hotspot for public executions and dissections.

A floating cat sanctuary on an Amsterdam canal.

The largest collection of handbags in the world, the oldest of which were used to carry Bibles, primarily by men.