This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

An ancient octagonal weather station named for the eight Greek gods of wind.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Museum dedicated to the terror regimes of Hungary.

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 favorite with sightseers, this Norwegian funicular provides easy access to a stunning view of Bergen and its environs.

An alien church provides much needed silence in the midst of a Finland shopping center.

A subterranean house of worship carved right out of the bedrock.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

Stockholm's deepest subway station is also a stunning ecological wonder.

The library's graceful rotunda is like a bibliophile's temple.

It houses the remains of a 17th-century version of the Titanic.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

Nordic giants resurrected from the sea and restored to their former greatness.

The oldest amusement park in the world has been providing a nice spot to have some fun since the 1500s.

A collection of noses tucked inside an art museum reveals how times have changed.

This colorful artistic feature atop a Danish art gallery allows visitors to stroll through a rainbow.

Six beautiful wooden giants are hidden around Copenhagen.

A 19th-century subterranean reservoir repurposed as a contemporary art cave.

The only surviving piece of Copenhagen's 16th-century defensive wall.

The art museum is decorated with creatively remodeled pre-Nazi swastikas.