The secret cells in the basement of the KGB's Estonian "Grey House" have been preserved as a grim Cold War museum.

This charming Latvian lane doubled as Baker Street on the Soviet Union’s version of Sherlock Holmes.

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

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

Flamboyant architecture from the turn of 20th century.

A former Latvian headquarters of the brutal KGB secret police is now open as a grim reminder of their atrocities.

An extensive collection of some of the oldest grave markers in Lithuania.

An old hill fort covered in over 100,000 crosses is a symbol of Lithuanian nationalism and beliefs.

Plaques celebrating Lithuanian writers freckle a wall of this picture-perfect path.

This micro-nation may be some sort of prank, but its constitution sure seems official.

Travelers who fall victim to this mermaid's charms are destined to stay in Užupis forever.

A 15-foot-tall statue of the head of the Sopranos family greets passengers at a train station in southeastern Lithuania.

Over time, this castle grew to encompass the entire island.

The world's first invisible city square is an homage to a man who pushed the boundaries of art.

A triumphant marble and bronze fountain depicting a 15th-century Hungarian king and his hunting party.

On Gellért Hill, this statue depicts the tragic tale of lovers divided by the Danube.

Tucked away near more famous landmarks lies a statue meant to symbolize the confluence and continuing development of human culture.

Something's watching you.

This hauntingly beautiful cemetery outside a medieval citadel is full of winding paths and ivy-covered graves.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

A striking symbol of the Bulgarian capital.

Underneath this Byzantinian church lies a necropolis filled with ancient tombs and the ruins of previous churches.

This building has two facades of clashing architectural designs.