(population: 35,200) is a town in the north-western Netherlands
, in the province of North Holland
. The municipality covers an area of 55.42 km²
(of which 5.66 km² water).
The municipality of Castricum also includes the following towns, villages and townships: Akersloot, Bakkum, Bakkum-Noord, Castricum aan Zee, De Woude, Limmen.