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

Eighty million natural history specimens call this gargantuan museum home.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

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

An 18th-century Spanish watchtower made entirely of seashell and concrete.

A tribute to Ponce de Leon's supposed quest for eternal youth.

It's a pretty creepy lock-up.

St. Augustine's record-setting narrow street was designed to protect against pirates.

A luxurious 1880s hotel with its fair share of Tiffany stained glass, Edison electricity, and of course, ghosts.

The only Florida state park with publicly accessible caves.

One of the world’s largest and deepest freshwater springs, where mastodons once roamed.

A tribute to a future time when gravity is conquered.

This abandoned NASA launch site is now a memorial to a trio of astronauts who were killed there.

A building so large that it has its own weather.

The unique collection includes bronze cast handprints of some of America's most famous astronauts.

This kitsch eatery is chock-a-block with bric-a-brac.

One-time winter retreats of prolific inventor Thomas Edison and his friend Henry Ford.

In Florida, these naughty monkeys live on their own mini-monkey Alcatraz.

Disney World's very first waterpark is now an abandoned ruin being reclaimed by the swamp.

An icon among Florida's pre-Disney tourist attractions.

Disney's abandoned animal island is now an overgrown ruin that was almost the coolest attraction ever.

Electrical pylon in the shape of Disney's beloved mouse.

A Florida college boasts the world's largest single-site collection of structures designed by Frank Lloyd Wright.

This small museum gives visitors a chance to soak up the history of the "sponge capital of the world."