Remnants of the most densely packed city in world history, that thrived on anarchy for 30 years.

The world's longest outdoor covered escalator system transports commuters through Hong Kong's hilly terrain.

Teeming with illegal goods and services, this towering maze of vice is also a popular tourist accommodation.

The spot in the Mile-High City that's exactly 5,280 feet above sea level (at least for now).

These ancient sunken lanes were naturally tunneled into the soft ground by countless footsteps.

Naked scientists race around the pole in the frigid cold to try to join Antarctica's exclusive 300 Club.

The world's oldest bookshop still in operation.

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

A stone marker memorializes the spot where the King broke up a street fight with a classic karate stance.

One of the last full-orchestra recording studios in New York City and an acoustical marvel.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

The world's largest key collection features keys to the White House, Frankenstein's castle, and Hitler's bunker.

An abandoned giant glass dome sits in the bay in “the Venice of the East.”

The nearly 200-year-old folly has a secret spiral staircase hidden in one of its pillars.

The alleged birthplace of Lady Jane Grey, who was executed at age 16 for claiming the throne of England.

Though its celestial ceiling is impressive, the true star is the vast collection of French books.

"The Donut" was built as part of an expensive, ill-fated engineering endeavor.

The show's fictional Korean medical camp was created in the Santa Monica hills.

A 6th-century stone lies at the site of the mythical battle waged between King Arthur and his nemesis Mordred.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

A tiny red pebble marks what may be the quietest outdoor spot in the United States.

Light still pours into the ruins of this ancient Islamic observatory.

The world's second-largest sundial, made entirely out of stone.

The largest guitar store in the world has been visited by some of music's all-time greats passing through upstate New York.