This temple to the sturm and drang of Richard Wagner contains a dragon's cave and reptile zoo full of living "dragons."

This former Nazi castle was built as a school to train what would have been the future of the Third Reich.

An amusement park on the grounds of an unused nuclear power plant, with a swing ride inside the cooling tower.

The small alleys in Lübeck's Old Town are a result of medieval urban sprawl.

This strategic isle was once swapped between empires and almost entirely destroyed in a bomb explosion.

This artificial cave looks like something out of a fairytale.

Walk through Czech history in Prague's largest graveyard.

The soulless eyes of 82 bronze children stare on forever in remembrance of a horrifying World War II massacre.

This former quarry is now a picturesque gorge that hides a sunken lake.

An old asylum graveyard that's been abandoned for half a century attracts those seeking a dark thrill.

Europe's largest natural bridge has a 19th century royal chateau built into its side.

Created as a "model concentration camp" to hide Nazi atrocities from the international community, this former camp-ghetto now holds a museum and memorial honoring the lives lost within.

The 14th-century ruins are said to contain healing powers.

This ruined castle perched atop a rocky peak is a great place for a hike.

A spiral staircase twists to the top of this unusual Czech lookout tower.

Visitors flock to the historic birthplace of radiobalneology for its therapeutic radium treatments.

This network of conjoined cellars was riddled with traps and supposedly allowed the townspeople to pretend their homes were deserted.

The deepest sinkhole in Central Europe comes with a grisly tale and an unusual nickname: “The Stepmother Abyss.”

A massive 1830s industrial site once known as Czechia's "Iron Heart" has been transformed into a playground of science, technology, and art.

A somber memorial honors the hundreds of thousands of lives lost at this labor and extermination camp.

This 700-year-old structure is one of the most unique architectural and historic monuments in Gdańsk.

The site of the first battle of World War II.

A World War II torpedo launch station abandoned off the Polish coast.

This imposing 20th-century castle was abandoned before it was ever completed.