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

A peculiar clock commemorates a historic victory won by ringing the noonday bell an hour early.

This impressive castle looms over small German town.

The prototype for all Nazi concentration camps.

This Nazi-built amphitheater was constructed on a sacred mountain site used by various German cults.

A triumphal steel arch on the side of a German mountain.

This mine is home to the largest man-made hole in Europe.

Lombardy poplars planted to imitate the size and shape of the Cathedral of Notre-Dame de Reims.

Unchanged for centuries, this medieval library keeps its books in chains.

An amusement park on the grounds of an unused nuclear power plant, with a swing ride inside the cooling tower.

The struggle of a small Dutch island against the sea.

Home to the world's oldest functioning orrery.

A farm turned upside down.

The private train station King Leopold II built for the Belgian royal family now lies abandoned.

The world's tallest boat lift stands as a massive piece of industrial tourism.

This old, abandoned hotel offers magnificent views.

A moving memorial to the fallen and missing from WWI trenches.

A rare example of World War I trenches from the British front.

In the shadow of a former battleground, the resting place for nearly 2,000 soldiers who died in World War I.

In an area where the remnants of WWI are discovered on a regular basis this preserved frontline trench may be the most amazing.

This narrow Ghent alleyway is an officially sanctioned street art tunnel.

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.

Scale model of St. Peter's Cathedral (Rome) in the middle of a small Dutch town.