The Batterij aan de Sloterweg is one of several forts that make up the defence line which was used in the late 18th and 19th centuries to protect parts of the country from invasion. It was designed to be a relatively inexpensive defensive mechanism – a series of canals and intakes would be used to transport water to flood the polders and make them impassable. Most of the forts are no longer operational, but are preserved as national monuments and are open to visitors.
