This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

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

A room in New York City that contains 250 cubic yards of dirt worth a million dollars.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

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

A semi-scholarly approach to sex.

Elevated freight railway turned wildly successful urban park.

A terrific purveyor of natural history objects and curios.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This Paris art space celebrates the creativity and ingenuity that springs from abject poverty, especially in Africa.

Notorious artist squat renovated into legal studios.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

A surrealist timepiece by the artist of melting clocks.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This museum houses an imposing skeleton army comprised of creatures great and small.

A museum of carnival attractions where you are invited to ride the rides.