The tallest stone dam in Poland was opened by Kaiser Wilhelm II himself.

This line of 12 tower mills described in the story of Don Quixote is among the most iconic landscapes in Spain.

Tallest - but not most powerful - wind turbine in the world.

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

This viaduct serves as a reminder of World War II.

One of Belgium's oldest hospitals saw patients from the 13th to 20th centuries before becoming a museum.

This "social palace" housing complex created a relatively stable and self-contained worker's society... for a time.

The not-quite-incorruptible St. Bernadette is perhaps the most beautiful of preserved saints—with a little help from Paris.

A cave dwelling that was started by the Celts, expanded by monks, and finished by knights.

This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

The remains of 40,000 humans, meticulously stacked in a tiny churchyard shed.

The world's tallest bridge is also possibly the most elegant.

A well-preserved medieval village nested on a rocky outcrop and surrounded by a network of cliffs, natural bridges and canyons.

A centuries-old quest to create artificial life is alive and well in the French town of Limoux.

For a few short weeks in spring, this hiking path becomes a daffodil paradise.

A neighborhood church's unusual abstract stained glass was the final project of avant-garde artist Jean Cocteau.

A colossal sculptural lion built by the same man who designed the Statue of Liberty.

Today this former Nazi concentration camp stands as a poignant memorial to the victims of fascism, and a warning from history.

An ancient monastery, a locked room, and a mysterious book heist.

A copy of the Statue of Liberty greets visitors to the birthplace of Auguste Bartholdi.

This unusual piece of Renaissance art depicting the bodily horror of crucifixion and skin disease may have been inspired by fungus-induced hallucinations.

The castle was reconstructed to fit Kaiser Wilhelm II's romanticized vision of the Middle Ages.

Wander among free-roaming storks at the sanctuary that helped save them from local extinction.

The world's most famous cheese caves.