Cryptic messages embedded in the New York City sidewalk.

Oldest existing church in New York and the inspiration for Washington Irving's "The Legend of Sleepy Hollow."

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Rat sculptures try to infiltrate the Graybar Building in an architectural tribute to New York City's nautical history.

There must be a pun in this haystack somewhere...

A bit of retro transportation flair preserved in the world's largest department store.

Yo, Adrian!

1513 Turkish world map, full of European state secrets and snarky commentary.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

Longest fortress system anywhere in Europe.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

This one-time health resort was used by aristocrats around the world.

Where the lovelorn find a home for their sentimental keepsakes.

A whimsical bridge adorned with decorative dragons.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

Large Hadron Collider and the Birthplace of World Wide Web.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

The final resting place of the great navigator, or maybe his brother.

The world's largest wooden structure.

A miniature village mimics the surrounding buildings so well it includes itself.

The Cambridge pub where Francis Crick announced that he and James Watson had discovered the DNA double-helix.