A relic of the Cold War tucked away in the forested hills above Bratislava.

Admire dozens of life-size animals made from old scrap metal, nuts, screws, and valves.

This region of Slovakia boasts some of the most plentiful opal mines in the world.

A gorgeous stone viaduct crosses over a bucolic valley.

The ruins of a 13th-century monastery that long served as a place of refuge from wars and raids.

An extraordinary museum devoted to the pop art legend created by Slovak artists.

A line of disused military bunkers built to defend against Nazi invasion lies hidden on the outskirts of the city.

A once-fairy tale mansion now stands in a state of disrepair.

The world's newest astronomical clock is also its most accurate.

A perfectly preserved hill village where the buildings are painted like white lace.

The blood-soaked ruins of the castle where the murderous Blood Countess was walled in alive.

For 200 years, people have flocked to this Polish town to experience the healing powers of salt.

The tallest stone dam in Poland was opened by Kaiser Wilhelm II himself.

These beautiful castle ruins are nestled in the Polish countryside.

This dazzling wooden church was constructed as part of an elaborate peace project after the Thirty Years' War.

A Bauhaus co-founder designed this quirky, abandoned granary.

During the renovation of this bas-relief, the constructors added one unusual element.

A small square populated with giant birchwood sculptures.

This wooden mosque is one of the few remnants of medieval Poland's Muslim Tatar community in this deeply Catholic country.

A Soviet era flat that refused to conform to the dull gray standards.

This abandoned but well-preserved Prussian fortress sits abandoned in a Polish forest near the German border.

The center of this Polish border town was so thoroughly wiped out in World War II that only the foundations remain.

This formerly-prosperous Silesian mining town was completely demolished in the late 1960s and early 1970s as an attempt to cover up a secret Soviet uranium mine.

One of the world's largest amber altarpieces is housed within this reconstructed medieval church.