No one is sure if the world's fourth-largest diamond had been found in a rubbish heap or was pawned by Napoleon's mom.

Ancient serpentine sacrifice holder that has stood the test of time.

This half-forgotten fortress was constructed by the Ottoman conqueror of Constantinople.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

This crucial gathering spot along the "hippie trail" still displays old notes between traveling beatniks and backpackers.

An Art Nouveau gem hides beneath the layers of city grime obscuring this once-magnificent building.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

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

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

A marvel of Byzantine engineering under the streets of Istanbul.

Over 70 independent businesses have set up shop in this former Victorian department store.

The largest Victorian water tower in Britain.

This public bathroom is guarded by a flyswatter-wielding army major.

Constructed during the 7th century this is one of the oldest largely intact Christian churches in England.

This ancient causeway can flood daily, leaving Mersea Island as a true island for hours at a time, and cutting its 7,000 residents off from the mainland.

The original toys that inspired the beloved children's stories are on display at the New York Public Library.

Decrepit Victorian public lift is a white-knuckle ride.

One fisherman has used his love of pebbles and shore to create a crazy garden of rocky art.

These seaside shelters once enjoyed by royalty remain a part of local history.

A vintage penny arcade hidden in the back of a fun fair-themed bar.

The rotting skeleton of a shoreside fun fair that was destroyed by fire and storms still haunts the Brighton ocean view.

These shopping center benches are actually a modern art installation.

This tiny alleyway is now a shrine to a subculture riot between the mods and rockers.

The last of Amsterdam's original sea level markers remaining in place.