A 700-year-old drinking fountain turned charity for the less fortunate of Zurich.

This massive boulder was hurled into a Zurich church when a gunpowder depot was struck by lightning in 1652.

Use a key to unlock this medieval sewer tunnel.

Visit the remains of a notorious Victorian-era correctional facility.

A never-finished memorial to the heroes of the Napoleonic War has become "Scotland's Folly."

An artist's whimsical transformation of everyday objects.

This extinct volcano rises above Edinburgh and is special for its panoramic views over the city.

These spooky and unusual stone formations create an underworldly landscape.

The tallest outdoor elevator in Europe rockets passengers on a dizzyingly precarious ride to the top of a mountain.

Bell tower juts out from a village buried under a lake.

This work of engineering is imbued with elegance and ingeniousness.

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

Op-art architecture designed for happiness.

Along the edge of this fountain are 365 smaller fountains that represent the days of the year.

Baroque celebration of the end of the Great Plague of Vienna.

A mechanical clock built in 1914, with a rotation of 12 historical figures on its face.

The solemn exterior conceals an opulent interior of this 17th century church.

An exquisite Baroque church in Vienna's old town.

This spire on an Austrian mountain is wrapped around a long spiral slide and has the world's tallest wooden observation deck.

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

Designed as a reminder of one of the darkest moments in Austrian history.

In the middle of a Vienna square, Roman ruins dating back some 2,000 years are on display.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.