Maassluis (Dutch pronunciation: [maˑˈslʌy̆s] ⓘ) is a town in the western Netherlands, in the province of South Holland.

During the Eighty Years' War, Philips of Marnix, lord of Sint-Aldegonde, started to build a defense wall but before its completion, the Spanish captured it in 1573[5] and Philips of Marnix was taken prisoner.

This separation may have been religiously motivated: Maassluis was predominantly Protestant and Maasland Catholic.

Construction stopped for five years because privateers from Dunkirk raided fishing boats from Maassluis, throwing their crew overboard.

Built from 1730 to 1732 by Rudolf Garrels, a pupil of Arp Schnitger, it was a gift by Govert van Wijn, ship-owner from Maassluis.

van den Tak merged to become Smit-Tak, now a division of the world's largest salvage company, Smit International.