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

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

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

An abandoned Jewish sanatorium is tucked within the woods of Poland.

In northeastern Poland, the ruins of a massive granary overlook the Narew River.

Relive a Polish uprising via an enormous, century-old cyclorama.

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

These massive moving sand dunes have swallowed an entire village and are still on the run.

Dubbed "Wistom" by locals, this abandoned factory is an urban explorer's dream.

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

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

Crosses of all shapes, sizes and colors litter the mountain, the site of a huge yearly Orthodox pilgrimage.

The majority of the highest mountain in Poland is actually located in a different country.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

This centuries-old wooden wonder was built in less than a year and is one of Europe's largest timber-framed churches.

Naturally formed rock city in Poland.

Countless stories attempt to explain Poland's mysterious J-shaped trees.

The excellent Swiss museum of witchcraft is led by a modern witch.

These spooky and unusual stone formations create an underworldly landscape.

A communal oasis on Lake Zurich.

The last woman executed for witchcraft in Europe is remembered in this Swiss museum.

This medieval footbridge in the Swiss Alps is known to attract cliff-jumping daredevils.

If James Bond bungee-jumped off the side of a 720-foot dam, would you do it too?

A breathtaking bridge that crosses a vast gorge over a river's torrents, and has a tale of a devil architect attached.