A German apartment building hosting as many trees as human occupants.

One of only two places in the world where two rivers cross each other without the waters mixing.

The hollow trunk of this 650-year-old tree was used as a hideout by two Jewish brothers during World War II.

A peculiar family mausoleum built by a German nobleman captivated by the occult.

Gliwice Radio Tower, likely the tallest wooden structure in the world.

Poland's oldest salt mine has nearly everything one needs to live underground forever.

There are thousands of tributes and memorials to the King, but none quite like this one in a Kraków city park.

The unsettling remnants of a torn down movie set lies nearby the ruined location of the actual Płaszów Labor Camp.

This man-made mound monument was built out of soil from all across the Polish empire.

Poland's oldest surviving university building holds a wealth of historic science instruments including some used by Copernicus.

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

Boats must transform into railroad cars to navigate this Polish canal.

An artificial hill and apparent calendric structure built in the Early Middle Ages immortalizes a legendary Polish princess.

In the midst of a living monument to Soviet social engineering, Polish Catholics built this church by hand.

An abandoned Nazi explosives plant founded by the inventor of dynamite is now an underground museum.

The relics are stored in a silver reliquary, where they can be seen through glass.

A miniatures park with a model of Wolf's Lair as it looked during World War II.

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

A marker honors the brief peace found by a tormented artist in the fictional land of Kcymaerxthaere.

Disturbing works of outsider art, carved from whole logs.

Brought to you by the makers of fiberglass dinosaurs.

Old cabin-like homes in a rural community untouched by time are known for their vibrant and colorful window shutters.

Thanks to its heroic service during WWII this Soviet castle has been turned into a monument towered over by a brutalist titan.

Museum dedicated to "the man who moved the Earth."