In this brilliant blue spring in Germany, legend has it that a sad mermaid learned to finally laugh.

The narrowest street in the world is in danger of closing up entirely.

The world's tallest church tower reveals a spectacular view to anyone up to the task of climbing the daunting staircase.

One of the world's heaviest musical instruments towers within a popular urban park.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

Berlin's old airport.

A city's controversial tribute to its founder depicts townspeople flashing their bare behinds.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

Berlin's natural history museum houses the world's largest mounted dinosaur and the late beloved polar bear Knut.

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

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

Uh, pardon me, ma'am, but I couldn't help noticing that there's a Columbo statue in the middle of Budapest.

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

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

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

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

Sofia's legislative center is continuously reinventing itself.

"Holy Wisdom" overlooks the city that became its namesake.

A vast Communist-era exhibition space in the Bulgarian capital.

This ancient theater, restored in the 20th century, lives on as a venue for dramatic and musical performances.

A striking symbol of the Bulgarian capital.