This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

The barrel-made lookout from Shackleton's final ship is tucked away in the crypt of one of London's oldest churches.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

An artist's cute bronze subway sculptures belie his violent artistic past.

The former hotel where Tesla invented the radio.

A whimsical, but often overlooked clock in Park Avenue.

A semi-scholarly approach to sex.

Red frames showcase remnants of one of New York's original subway stations.

The most confusing clock in New York.

A terrific purveyor of natural history objects and curios.

Nope, not Washington Irving's house.

A trove of century-old litho stones from the Puck Building's printing days were discovered behind a cellar wall, and are now hanging in the store.

New York City's only preserved family home from the 19th century.

This exemplar of modernist architecture is meant to captivate and inspire students of the Cooper Union.

A hidden "place of interment for gentlemen."

Become a prohibition rebel.

Enormous one time fiber mill now houses local artists and small businesses.

Walk into the 19th century without leaving Brooklyn.

Queen Anne style apartment house built in 1886.

A charming "tea atelier" hidden away in Greenpoint, Brooklyn.

Constructed in the 1920s, this former pencil factory is now an office building.

Ornate "Renaissance Revival" style building.

Leaf through over 30,000 artists' sketchbooks in what may be the world's largest collection of doodles