The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Catacombs turned marketplace.

This impressively complicated radioastronomy research center was once a tool of Soviet spies.

Guests become prisoners on a visit to Latvian prison.

A top secret Cold War bunker hidden beneath a Latvian spa facility is now open for tours.

These crumbling Latvian forts make for some haunting seaside ruins.

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

A vast and unlikely aviation museum kept alive for over 50 years due to one man's tenacity.

Latvia's symbolic mountain-shaped national library is home to millions of cultural tomes.

A preserved oak tree about 3,500 years old found in Riga, Latvia.

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.

A former imperial sea-fortress and Soviet prison.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

Sitting beneath an unremarkable residential building is a museum devoted to classic Pinball.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.