The largest salt lake in the Sahara is mysteriously alluring.

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

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

The largest and best-preserved Roman amphitheater in Africa was designed to seat 35,000 people.

Buildings from the fictional planet of Tatooine still litter the Tunisian desert.

Metro station with a claim to rock n' roll fame.

Beneath the impressive baroque cathedral that rises from the center of Berlin lies the largest collection of Prussian royals in the world.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

The most visited, and possibly most controversial, museum in Germany.

Flamboyant architecture from the turn of 20th century.

Perhaps the tiniest sculpture in Saint Petersburg is a little bronze finch inspired by a song.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

A scale model of Russia so big visitors are offered binoculars to rent so they can see the whole thing.

The oldest museum in Russia is home to a fascinating collection of nearly two million anthropological artifacts and anatomical curiosities.

This 15th-century cave complex is one of the very few monasteries to stay open throughout World War II and the Soviet regime.

First point in the Struve Geodetic Arc, a 19th century undertaking to measure the Earth's size and shape.

Historic slum of Tartu.

An abstract monument to a symphonic composer.

The ruins of an Estonian prison are drowning in the quarry lake where the convicts were once forced to work.

An alien church provides much needed silence in the midst of a Finland shopping center.

This endearingly discomfited urinating statue commemorates the sneaky pees had by us all.

A forest park outside Tallinn full of architectural and artistic curiosities.

A series of concentric circles represented a bold new experiment in socialist urban planning, and it notoriously difficult to get around.