The remains of Crystal Palace Great Exhibition of 1851.

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

Hear the quietest sound from across the dome.

Remnants of a Victorian garden feature sitting in public woodland.

A historic London pub with prison cells in the cellar and a "spy room" on the second floor.

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

An unusual round church in London with a Templar past.

Catacombs turned marketplace.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

Eighty million natural history specimens call this gargantuan museum home.

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

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

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

A kaleidoscopic warehouse-maze of handmade neon signs.

A Saxony castle houses one of the largest and most outstanding mineral collections in the world.

The sanctuary holds what was once believed to be the saint's incorruptible tongue.

One of the famous Czech artist's lesser-known Prague installations appears to be a glowing fetus affixed to a drainpipe.

Inside this Jewish cemetery is a memorial to soldiers who deserted the German army and were executed.

This 11th-century Greek monastery has renowned mosaics and relics of a brutal past.

This coffee shop lies hidden beneath a historic church.

Stroll past dozens of intricately-detailed scale replicas of buildings from all over Czechia.

Peek into a cave of giant, glimmering crystals.

An uninhabited village that preserves and documents rural architecture and an endangered way of life.