Military locations

Organisation Todt, Nazi Germany's construction company, sent an army of forced labourers to an old marl quarry in the Netherlands in the spring of 1944 to convert it into an aircraft engine maintenance site.

Three mysterious concrete structures stretch over a distance of hundreds of metres.

L'ouvrage du Four-à-Chaux was one of the gros ouvrages or large artillery works of the French Maginot Line. Yet almost nothing of it can be seen above ground.

As if the Atlantic Wall defensive strongholds in the Ostend dunes were not enough, Nazi Germany erected a second line of defence in the hinterland.

In 1990, a Sherman tank was parked at Balgerhoeke lock in Eeklo in honour of the Canadians who liberated the town from German occupation on 15 September 1944.

Anyone entering Nieuwpoort via Kinderlaan will come across the remains of the World War II German Widerstandsnest Karthauserdünen.

The Castillo de la Monta atop the 123-metre-high Monte Urgull has watched over the Spanish coastal city of San Sebastián since the 12th century. 

The German army fenced off the border between Belgium and the Netherlands from 1915 with a three-wire fence. Electric current of 2,000 volts was rushed through the middle wire.

In 1815, after Napoleon's defeat at Waterloo, Dutch King William I gave the go-ahead for constructing the New Dutch Waterline. This defence line extended over a distance of 85 kilometres between the Zuiderzee and the Biesbosch.

The Spanish Empire once spread over much of the world, but the Spanish-American War of 1898 dealt the global empire a death blow.