You can still see bits of the camouflage used to hide this Art Deco building from bombers during World War II.

The broken skateboards that became a poignant memorial to a murdered skater.

An exercise in radical design and social living that became the epicenter of Soviet spy networks in London.

An eccentric Victorian aristocrat's enormous collection of medieval armor and weapons from around the world.

Though it's not the largest, this one-kilometer outdoor market is reportedly the longest in Europe.

Shiny Brutalist box commemorates a pioneer of electricity and houses a railway transformer.

This ancient oak plays host to carvings of magical elves, gnomes, witches, and other creatures prominent in local folklore.

In Twickenham sits a small whitewashed castle that inspired Mary Shelley's 'Frankenstein.'

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

Public access to clean drinking water was an instant hit among the masses.

Explore nearly 400 years of English middle-class home life.

A Victorian natural history and ethnographic museum with wonderful turn-of-the-century, science-book-esque evolution displays.

London's old-school healing garden.

The anatomical-pathological collection of a man who changed surgery.

One of Madrid's oldest trees, with a long and colorful history, resides in El Retiro Park.

Meant to resemble a massive tree, the building is the best example of Spanish organicist architecture in Madrid.

Nicknamed the "Spirit of Paul Klee," this colorful apartment building features an array of multicolored panels.

A towering monument in Spain has proven to be more labor-intensive than initially planned.

Five million people are laid to rest here, more than the population of Madrid itself.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

An exact replica of a colossal Olmec head sits atop a pyramid within a Madrid traffic circle.

This lucky bronze frog was gifted to Madrid by a casino.

This funky former tobacco factory is one of the most striking examples of Madrid's cultural diversity.

One of the world's oldest universities houses an incredible collection of anatomical models, mummified body parts, and human bones.