This historic observatory contains the world's oldest refracting lens telescope.

An 18th century wonder of the world, lost in WWII, re-created at the Catherine Palace.

The corpse bride of Portugal.

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

Moscow's imposing monument to the Space Age.

Moscow's most popular cemetery includes the graves of numerous cosmonauts.

This famous archeological mystery may be an ancient example of movable type.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

The design of the Palacio Salvo has been described as "a lighthouse on top of a building."

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

The cafe that acts as the social hub for the small volcanic island of HMS Bounty fame.

An island in the middle of a lake, in the middle of a volcano, in the middle of a bigger lake, in the middle of a bigger island, in an archipelago, in the Pacific Ocean.

A marvel of Byzantine engineering under the streets of Istanbul.

Macabre astrological automaton clock dating to the late 1400s.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

San Francisco's newly reopened hands-on science museum.

The world's most active stratovolcano is almost always erupting.

The watery grave of Captain Bligh's famous ship.

The hallucinogenic center of the ancient world.

A contemporary art installation housed within a Gothic cathedral.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

Two plaques commemorate the site of Shakespeare's first theatre.

Home to three historic ships from the age of Vikings.

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