An underground city of salt.

An artificial hill and apparent calendric structure built in the Early Middle Ages immortalizes a legendary Polish princess.

This sprawling concrete suburb of Kraków was designed by the Soviet Union as the model proletarian city.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

Real bones which are said to have belonged to a Polish dragon.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

A statue honors the children who fought Nazis in Poland.

After the famous composer died in Paris, his sister snuck his heart out of the country to honor his wish that it be buried in their native country.

This extensive collection covers thousands of years of Polish military history.

An artificial date palm stands as a memorial to Warsaw's Jewish community.

The statue of a legendary giant who carried Christ and shouldered the world's sins.

3,000 market stands in five former Zeppelin hangars.

A statue built to honor the elite soldiers who fought for Latvia during World War I.

The reconstruction of this prominent building fulfilled a long-written command.

This celebration of Latvia’s freedom and independence avoided demolition over half a century of Soviet occupation.

Traditional 11th-century outdoor tannery.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

Morocco’s modern capital was once a haven for Barbary pirates, who went so far as to establish a republic of their own.

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.

A fortified city, home to a remaining population of five families

Walk along the medieval fortifications that have been protecting Tallinn since the 14th century.

The Guardian of Tallinn.