This Hungarian stilt village is built in a lake that never freezes over due to the power plant that that uses it as a cooling pond.

An abandoned saucer-shaped monument in the Bulgarian mountains.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

Moss and stone turn this waterfall into an otherworldly liquid veil.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

This massive underground salt mine now holds a sci-fi theme park in its depths.

This Romanian village may have been drowned, but it is long from forgotten.

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

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

A former ironworks that was the first UNESCO industrial site.

A Black Forest cuckoo clock theme park features one timepiece big enough to walk inside.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

Built to test magnetically levitated elevators, the tower also boasts Germany's highest visitor platform.

This 170-year-old Swiss guesthouse built into the side of a mountain is best accessed by a cable car.

This sprawling Belgian fort was once thought of as impenetrable but now it is simply an abandoned relic.

Lavish royal estate punctuated with heated greenhouses.

This ghost town in Belgium will lose its street art when it ceases to exist.

Over 3km of caverns and caves at the Switzerland-France border contain the largest underground river in Central Europe.

The shape of this old salt factory complex was inspired by the course of the Sun.

A Christian retreat founded to welcome refugees fleeing from the Nazis during World War II.

This former limestone quarry is now a subterranean wonderland of grand stonework.

This natural French spring has been turned into a magical grotto by Roman and medieval constructions.

An unusual sand beach in the middle of a forest.

A village of art and exotic creations.