The Orange Locks are a complex of lock locks in the IJ and form the boundary between the Binnen-IJ and the Buiten-IJ. They contribute to maintaining the water level in the North Sea Canal and ensure that not too much salty water from the North Sea Canal ends up in the IJsselmeer . The locks are managed by Rijkswaterstaat. The complex extends from the village of Schellingwoude on the north bank of the IJ to the northern point of the Zeeburgereiland. The lock complex comprises three smaller locks intended for small commercial and recreational craft, a large lock for inland shipping, and two fish passages. The smaller locks have doors that can be opened and closed. The lock gullies of these locks measure 14 by 67 meters (two pieces) and 18 by 90 meters. The large lock, the Prins Willem-Alexander lock added in 1995, has a chamber measuring 24 by 200 meters and sliding doors that slide over a hydro base, a very thin layer of water. The locks are operated from two control buildings. Every year about 120,000 ships pass through the locks and hikers and cyclists can cross the IJ over the locks.
In 1865, the first spade went into the ground for the digging of the North Sea Canal and the construction of the Orange Locks was also started. To properly regulate the water level in the canal, the IJ on the east side had to be closed off from the Zuiderzee. Initially they wanted to do this with a dam, but at the insistence of Amsterdammers and inland skippers it was decided to do this by means of a lock, so that shipping between Amsterdamand the Zuiderzee remained possible. King William III laid the first stone on April 29, 1870. At that time, the construction of the coffin dam that formed the largest part of the barrier had already been set back for five years. On September 25, 1872, the first ship passed through the lock. Dangerous situations sometimes arose due to the increasing crowds in the 70s and 80s of the 20th century when commercial shipping and pleasure ships wanted to pass the same lock. Inland vessels had also become much larger since 1872. That is why in 1995 a separate lock was opened for inland shipping, the Prins Willem-Alexander lock. Between 1997 and 2000, the old complex was radically renovated and modernized: the foundations were renewed and the locks were given double turning doors.