The Philipsdam and Krammer Locks with the Laagbekken one of the water basins of the saltwater and freshwater lock system. The locks have a unique system by which can be separated. It was intended to prevent too much salt water from the Oosterschelde flowing into the freshwater Volkerak or too much freshwater flowing into the Oosterschelde when ships were passing..© 15 aug 2016 Marco van Middelkoop/Aerophoto-Schiphol