Ĳmuiden is a town in the Dutch province of North Holland, the main town of the municipality of Velsen. It lies about 17 km (10.3 mi) north of Haarlem. In the Roman era, this Velsen district was already inhabited, and archeological finds indicate there was a North Sea port of some regional importance built here. The town suffered heavy damage and demolition during World War II, because of its maritime importance.
Ĳmuiden is a fairly new town in its present form, that only came into existence in the 1870s, when the North Sea Canal was dug, connecting the Amsterdam harbors to the open sea. Before the present Ĳmuiden has been built, the area was known as Breesaap, a desolate plain where only a handful of farmers strived to make a living. In 1851 the whole area was sold to the entrepreneurs Bik and Arnold, which finally set into motion the plans that had been drawn up already in 1626. The first spade hit the ground on April 8 1865. The Ĳmuiden name literally means “mouth of the Ĳ”, which is a hint to the importance the town has for the Amsterdam harbor. The name “Ĳmuiden” first appeared as Ĳ-muiden in lines written in 1848 by the professor and journalist (and, later, a liberal finance minister in the Van Lynden van Sandenburg Cabinet) Simon Vissering. The present Ĳmuiden form was eventually adopted in 1876, as the North Sea Canal was being completed in this section.
In 1890 it had about 1,500 inhabitants, but boomed when the Koninklijke Nederlandse Hoogovens steelworks settled in Ĳmuiden. The statistical area Ĳmuiden which includes the surrounding countryside, has a population of 30,466. The headquarters of the Koninklijke Nederlandse Redding Maatschappij is located in Ĳmuiden.
Besides the Velsen Municipality Hall (Raadhuis van de gemeente Velsen), designed by the famous architect Willem Dudok, important sights in Ĳmuiden are the North Sea locks. The latter are among the largest in the world and one set is able to close off a shipping lane of 50 meters (164 ft) wide and 12 meters (39 ft) deep. There are plans to enlarge or build a new set to facilitate even larger vessels.