Eduardo Kobra’s breathtaking 32,300-square-foot graffiti wall took over Rio’s Olympic Boulevard.

This massive Brazilian church is built like an angular, technicolor pyramid left by Mayans from the future.

A 125-meter long "tribute to the Brazilian people."

Catch a scenic view of Warsaw's Old Town from the top of a centuries-old dumping ground.

This lakeside bunker complex in Mamerki, Poland, housed the Supreme Military Command of Nazi Germany during World War II.

Built to transport German U-boats through the never-completed Masurian Canal, the locks near this Polish village are now home to a rope course.

This Communist-era residential block is one of the longest residential building in Europe.

This antique thermometer honors the creator of the first universal temperature scale.

A floundering Polish shipyard was once the soul of the Solidarity movement that capsized communism.

This 13th century Gothic brick castle is the largest in the world by surface area.

The Polish capital has had a deep connection to its guardian mermaid for almost a millennium now.

A statue honors the children who fought Nazis in Poland.

A huge wooden clock that is so beautiful its creator was forcibly blinded.

This sprawling concrete suburb of Kraków was designed by the Soviet Union as the model proletarian city.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

The site of the first battle of World War II.

A sculpture of graceful storks sits atop this fountain in Independence Square.

Glowing orb in Minsk houses 8,600,000 items.

Featured in one of the most iconic scenes in cinema history.

This derelict superstructure was a very important warning system for the Soviet military.

One of the most poignant ruins of the Chernobyl nuclear disaster, the local football team's stadium has been quickly reclaimed by nature.

This attraction was abandoned after the Chernobyl disaster.