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

A monument to the man who almost killed Hitler.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

Dedicated to the European Sinti and Roma peoples murdered during the Holocaust.

A French chateau, failed utopian community, odd museum, and Stonehenge replica in rural Washington State.

Allowing humans and fish alike to migrate from freshwater to saltwater and back again.

A wall of chewing gum moonlights as collective art.

This playground sculpture of an icon from the past is dedicated to the children of the future.

A 1940s nuclear reactor built to produce plutonium for the Manhattan Project.

The strange phenomenon causing gravity to "work backwards" on this hill has been blamed on the paranormal.

Nuclear reactor created the plutonium used on Nagasaki.

Dine amidst exotic plants at this former royal greenhouse.

The townhouse where the "Blood Countess" Elizabeth Báthory started her murderous career.

Designed as a reminder of one of the darkest moments in Austrian history.

Legends surround an ancient tree trunk riddled with nails for good luck.

A mechanical clock built in 1914, with a rotation of 12 historical figures on its face.

Baroque celebration of the end of the Great Plague of Vienna.

Across this single-file rope bridge is what has been claimed to be the edge of continental Asia.

Come for the flowers, stay for the bats!

Hidden within Sydney’s lush Royal Botanic Garden is a walled cactus rockery and the site of Australia's first zoo.

A futuristic, brutalist masterpiece that is also strangely prison-like.

Once the fallout shelter of a dictator, this sprawling bunker is now a combined history museum and contemporary art gallery.

This extravagant Art Nouveau rest stop features a million-dollar view of the Columbia River.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.