Fort Spion was part of the New Dutch Waterline. This defence line was erected between 1815 and 1885 and underwent several modifications until 1940, when it was last used as one of our country’s main lines of defence. These days, Fort Spion is home to a number of facilities, including a small and modestly equipped campsite. It is the perfect base for spending a few days on and around the water, between the river Vecht and the Loosdrechtse lakes.