Scattered throughout London are ancient remnants of the city's former bounding wall.

An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

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

Remnants of a Victorian garden feature sitting in public woodland.

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

A little slice of Japan and its aesthetics in London's Holland Park.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

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.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

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

The Spanish king's private bathroom embraced the idea of a porcelain throne.

King Carlos IV laid the first stone during construction of this chapel.

The remains of this misplaced church were moved here stone by stone.

A model solar system adds a celestial touch to this suburban park.

The lengthy skeleton of one of the tallest Spaniards of all time is on display in Madrid.

Among the oldest structures in Madrid, these Moorish walls once guarded the medieval city of Mayrit.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

A lush indoor jungle fills this bustling Madrid transportation hub.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

This house's itty bitty size means no humans allowed.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.