The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

The largest underground lake in Europe.

These spooky and unusual stone formations create an underworldly landscape.

The second-highest train station in Europe.

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

This amazing pedestrian suspension bridge in the Swiss Alps would give Indiana Jones nightmares.

This building’s ghostly exterior reflects its former lives as a prison, school, and funeral home.

Two standing giants remain as a tribute to Luxembourg's metallurgical past.

This Luxembourg cave is covered in cryptic looking marks left by mining activity.

This tri-part waterfall is a little bit of fairytale beauty in the heart of Luxembourg's Little Switzerland.

This noble mash-up in eastern Luxembourg is part Medieval, part Renaissance, all castle.

A 12th-century castle featuring a sensory path where partially-sighted visitors can experience regional history through touch and sound.

Once the local rulers had gone these enchanting ruins housed common folk in an almost real life fairy tale.

Dedicated to the American general whose reply to a German demand for surrender was simply "Nuts!"

The vast chamber inside this abandoned cooling tower looks like something out of a sci-fi dystopia.

Head underground and take a tour of the city's working sewer system, and see the underground river Senne, which defined Brussels for centuries before being covered in the 19th century.

This recently restored crypt was once plagued by liquefying coffins and exploding caskets.

Climb inside an iron crystal magnified 165 billion times its normal size.

The tallest church in Mechelen might have been the tallest in the world if not for a lack of funds.

Take a leisurely walk through the park to find the seven giant troll sculptures hidden throughout the park.

Rare wooden escalators lead deep down into an otherwise staggeringly monotonous tiled tunnel.

An open-air sewer system that was covered piece-by-piece over 300 years.

This statue dedicated to the story of a Flemish boy and his dog was relatively obscure in Belgium, but a cult sensation in Japan.

This former hydraulic laboratory is now a woodland dotted with old engineering models.