Founded in 670, this ancient mosque is an architectural time portal.

An ancient burial ground believed to have been used for ritual sacrifice.

Made famous by 'Star Wars,' these troglodyte homes face an uncertain future.

A daily pyrotechnic celebration marks a beloved tradition during Valencia's festival season.

According to the Guanches, the aboriginal people of the Canary Islands, the king of evil lives inside this volcano.

On La Gomera, "Silbadors" communicate in a 4,000-word language of whistles.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

The oldest housing complex in Riga is a mini timeline of architectural trends.

A black cat protests the City Guild in Riga's Old Town.

Flamboyant architecture from the turn of 20th century.

3,000 market stands in five former Zeppelin hangars.

1,500 Commonwealth servicemen of World War II are buried or commemorated in this cemetery.

Every spring, locals see the shadowy figures of a ghost army of slain Greek soldiers descend upon this ruined fort.

The oldest olive tree in Greece has been bearing fruit for at least 2,000 years.

Cave on extinct volcano, once home to famous mathematician Pythagoras.

Roughly 17 million letters to Santa have found their way to this Arctic Circle post office.

The church's remarkable frescoes incorporate Finnish artist Hugh Simberg's trademark themes of death and the supernatural.

A cathedral resurrected from the ashes of one of Europe's greatest urban fires.

These Finnish rapids have been attracting tourists for over a hundred years and are now released with the push of a button.

This irregularly shaped sea fortress has defended not one but three different sovereign states.

A 246-foot-high revolving restaurant rises unexpectedly from a forested Finnish hilltop.

The smallest restaurant in the world.

This insurance company building reminds customers that witches, bears, and gnomes are out there, best be insured.