A striking public sculpture representing the period of martial law in Communist Poland.

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

At first glance, this area seems like just another city park, but the lush landscape hides a dark past.

This biographical museum honors the groundbreaking scientist at her birthplace in Warsaw.

A national collection of Communist-era musical posters.

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

After the famous composer died in Paris, his sister snuck his heart out of the country to honor his wish that it be buried in their native country.

The site of the first battle of World War II.

A program of Communist glamour in post-Stalin Poland is preserved in this colorful museum.

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.

Sweden's "good old days" painstakingly re-created in a model village.

This is not only one of the oldest collections in Europe, but also possibly the most beautiful.

The haunting complex honors the millions of Ukrainians who died in the forced famine under Soviet rule.

The deepest metro station in the world.

One of the largest museums in Ukraine remembers the story of the German-Soviet War in iconic, brutalist style.

340-foot statue built to honour the Heroes of the Soviet Union.

A reconstructed medieval gateway that was the magnificent entrance to the capital city dating back to 1037.

This attraction was abandoned after the Chernobyl disaster.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

The bones of two medieval royal lions were discovered at the historic fortress.

These wire animal sculptures commemorate the exotic inhabitants that once called the Tower of London home.

The Tudor-style cottage in the middle of the square is not quite what it seems.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.