One of the most easily accessible examples of the rare 1960s UFO houses.

The scars of World War II are preserved on its walls.

A subterranean display of public art and architecture.

Golden cobblestones remember a time when this small alley was used to avoid having to give a Nazi salute.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

Named after the German word for "a longingness to travel," this park brings together thousands of city and street signs from around the world.

A preserved Nazi labor camp now has a Holocaust museum on site and memorials to the thousands that died while imprisoned at the camp.

The amazing wonder cabinets of a very rich Austrian archbishop.

The beautiful, ornate weather station is the most popular geocache in Salzburg.

Relics of Australia's convict past, and a modern scene of unimaginable horror.

The world's first cageless zoo is working to save endangered Tasmanian devils.

Built for the 1962 World Cup, this fully functioning botanical clock is still ticking.

A whimsical European-style chateau that calls the coast of Chile home.

What was once a unique system of urban elevators is turning into a mechanical ruin.

105-foot wide giant metallic flower blooms anew every day in the heart of Buenos Aires.

A bright little alley in La Boca is a part of tango history.

Equipped with thousands of LED lights, this geodesic dome-shaped stadium is an engineering delight.

It's just another skyscraper, but it's shaped like '90s cell phone.