The ridged layers that make up this river canyon represent Earth's geological history.

This mesmerizing medieval monastery-cave complex sits thousands of feet above ground overlooking a valley.

The bizarre rocks of Đavolja Varoš are the result of natural erosion.

This spaceship-like Serbian monument reaches for the stars in celebration of the fallen fighters of fascism.

This memorial park stands on the site of one of the largest mass executions of the Second World War.

A sinuous path among steep cliffs creates a stunning sight in southwestern Serbia.

This 14th century castle withstood years of battle but is now sliding off the hills into the Danube.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

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

The largest underground lake in Europe.

One of the highest emergency huts in the world has been waiting almost a century to give imperiled climbers a place to lie down.

A symbol of friendship between the mountainous regions of Switzerland and Bhutan.

Medieval irrigation channels built into the sides of mountains provided Valais with water for hundreds of years.

Devilish masks, handicrafts, and pieces of old buildings create a snapshot of life in a historic Alpine region.

A breathtaking viewing platform over the Alps.

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

Part ski resort, part modern art space, this lodge brings giant metal spiders and bloody doors to the Austrian Alps.

The shell of a medieval fortress offers commanding views of the area it once protected.

This series of underground chambers contains Europe's largest subterranean lake that is slowly drained each day.

Museum devoted to the artificial language of Esperanto.

The largest ice cave in the world is thought to be the entrance to hell according to Austrian legend.

A centuries old castle atop a dormant volcano houses museums devoted to both women and witches.

The first passenger cable car in the world.

On the outskirts of a desert trading village high on the Andean plain, steel giants have been destroyed by salt winds.