Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

A bronze replica of an elm tree that honors the victims that perished in Pawaik Prison.

The last king of Poland was interred in this church nearly 200 years after his death.

The final resting place of the last "gypsy king" of Poland.

In the summer, the area around this sculpture transforms into a vibrant concert venue.

This extensive collection covers thousands of years of Polish military history.

The giant statue and its model solar system honor the native Pole who declared that the Earth revolves around the Sun.

One of the world's largest collections of medieval religious art.

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.

The final resting place of more than 200,000 people, this is one of the largest cemeteries in Europe.

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.

A hidden art gallery in an abandoned Warsaw fort.

An abandoned swimming pool decays on the outskirts of Berlin.

The music is over at the Ballhaus Riviera Ballroom, but the ballroom remains in haunting disrepair.

A state-of-the-art medical facility from the Imperial era is now a derelict ruin.

This watchtower once presided over the Berlin Wall.

The original burial place of this preeminent 18th-century Jewish philosopher was razed by the Nazis.

This museum is home to a sugar sculpture of the Berlin Airlift Memorial.

One of the oldest cemeteries in Germany was originally used for victims of a cholera epidemic.

This concrete residential area doubles as an open-air gallery.

This sprawling Jewish cemetery is one of the largest in Europe.

Reminders of the Battle of Berlin still scar the railway.