The Volkerak locks, west of Willemstad, were built as part of the Delta Plan. A secondary dam had to be built in the Volkerak to close off the Oosterschelde and the Haringvliet. However, the closing off of the Volkerak, which was planned in 1969, would also block an important shipping route between Rotterdam/Germany and Antwerp/France. It was therefore decided to build a lock complex in the dam to be constructed.
The first two inland navigation locks were built in 1964. In 1977, the complex was expanded to the northwest with an additional lock for inland shipping, an inlet lock and finally a separate recreational lock. Bridges had already been built over the newly constructed locks: a fixed bridge and a double movable bascule bridge over the southern lock for commercial shipping. To the south of the locks are various service houses and a workshop and storage area for the emergency power supply and the nuclear shelter below. On the south bank of the Volkerak, at the beginning of the lock, there is a lookout tower, with a storage area for the reserve gates underneath. In addition, a new lock keeper's office was built around 2012; the old lock keeper's house between the eastern and middle locks was demolished shortly afterwards. At some distance from the locks on the south bank, there is another office and a door storage / workshop. In 1988, the complex was mentioned in the Guinness Book of Records as the largest inland shipping object in the world.
The commercial shipping locks are each 325 metres long and 24 metres wide. The locks are built of concrete and each has four pairs of steel doors; two pairs for ebb and two pairs for flood.