Off the beaten track in The Netherlands

Anyone walking through the dunes between Groot- and Klein Valkenisse on Walcheren will come across a remarkable sight: long rows of pyramid-shaped concrete blocks shooting up out of the sand.

In a quiet little park just north of Vlissingen, the Netherlands, you'll stumble upon the concrete remains of a German anti-aircraft battery from the Second World War.

In the early 1960s, a brutalist observatory rose from the ground on an expansive polder in Utrecht. From March 1964 onwards, students and astronomers could climb the so-called Star Tower to gaze at the sky.

During the Second World War, the historic naval harbour of Hellevoetsluis in South Holland grew into an essential stronghold within the Atlantic Wall, the 5,000-kilometre-long coastal defence system of Nazi Germany.

On 31 December 1974, the miners of the Oranje-Nassau I in Heerlen mined the last lump of Dutch coal, half a century ago.

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.

In 1951, the Hydraulic Laboratory De Voorst settled in the Dutch Noordoostpolder. There, scientists had a constant supply and drainage of water to test out scale models for hydraulic works.

One of the 138 Dutch air watchtowers was built in the 1950s right between the rivers Maas and Waal.

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.

With a bunker as its foundation and on top of a floodbank, Air Guard Tower 5K3 offered a broad view over the Hollandsch Diep and the Mariapolder beyond.