Originally this was the "Fort bij Heemstede (Fort at Heemstede)", completed in 1880 as part of the Stelling van Amsterdam (Defence Line of Amsterdam, which is a UNESCO World Heritage Site).
In World War I, the fort was demolished and 8 concrete bunkers were constructed. It was named "Voorposten bij Cruquius (Outposts at Cruquius)". Nowadays the bunkers still are present and they are part of a park.
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