Singapore's landscaping project is home to 18 incredible Supertrees.

Macabre astrological automaton clock dating to the late 1400s.

Cornish legend says these ancient circles were people turned to stone for playing hurling on a Sunday.

The largest stone circle in Ireland.

A rocky Irish outcropping with a history of wealth, conflict, and ruin.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

A building so large that it has its own weather.

Enigmatic bug-like sculptures mystify drivers along a Swedish highway.

A sweet museum focused on beets.

A historic fire call point.

This monumental work of art symbolizes the coming together of a previously divided city.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

This TV tower once secretly housed a GDR intelligence team.

After a nearly successful attempt on Hitler's life, the conspirators met their fate in the courtyard of this Berlin building.

Metro station with a claim to rock n' roll fame.

Cold war icon and onetime "hole" in the iron curtain.

A restaurant and observation deck built in a unique broadcasting antenna.

Berlin's old airport.

A 12th-century fortress containing some of Berlin's oldest buildings.

A tree-like building perches on its trunk in the Steglitz neighborhood of Berlin.

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

This Berlin island is home to a flock of free-roaming peacocks, as well as a historic ivory folly.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

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