A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

New York City's smallest piece of private property.

This unmarked and unloved Manhattan subway grate created one of the most iconic images in American cinema.

The oldest operating apothecary in the US has treated everyone from Thomas Edison to Mark Twain.

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

Read a book next to a Midtown waterfall.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

The "Seinfeld" diner.

Sniff the Titan Arum's rotting flesh.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

A semi-scholarly approach to sex.

Elevated freight railway turned wildly successful urban park.

Try not to get slimed in Tribeca.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

A terrific purveyor of natural history objects and curios.

The very first subway station in New York City is beautiful, decked out in chandeliers, and ... abandoned?

The grave of Mrs. Reginald Hargreaves, who inspired the tale 'Alice in Wonderland.'

This century-old grotesque has a mysterious history and may not actually be a rabbit.

One of the few standing Roman lighthouses and a labyrinth of tunnels are a couple of the secrets at this historic castle.

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

Dubbed Germany’s most accident-prone shopping street, this short stretch has seen around 30 cars crash into storefronts.

This German fountain of a legendary apple wine-loving drink thief will spit on you.

Lines on the pillar of Heidelberg's Karl-Theodor Bridge record the dramatic heights of past floods.

A larger-than-life monument to the inventor of the Bunsen burner.