In Costa Rica's cloud forest, the roots of a woody ficus create a botanical bridge.

These mysterious ancient stone spheres were created by a civilization lost to time and are now mostly lawn ornaments.

This neon blue river gets its color from a unique mix of bacteria and volcano minerals.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

A clock designed to run with perfect accuracy for 10,000 years.

A historic London cemetery now serves as a nature park incorporating gravestones & memorial statues.

This hidden green space is the city's second largest conservatory.

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

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

Catacombs turned marketplace.

A special shop catering to the needs of things that go bump in the night, and also helps kids become writers.

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

An unusual round church in London with a Templar past.

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

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

Eighty million natural history specimens call this gargantuan museum home.

A tongue-in-cheek arcade where the games are based on everyday life.

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.

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

A kaleidoscopic warehouse-maze of handmade neon signs.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

On October 17, 1814, a 15-ft. wave of beer ran rampant through the streets of London.

Classic game cookery takes center stage at what's widely considered London's oldest restaurant.