In 1799 a open battery was constructed on north of the fortress Muiden, called Westbatterij. This town was an important part of the Old Dutch Water line, since it protected both the important dike and the sluices of the river Vecht. In 1815 the Westbatterij was incorporated in the New Water Line. A major improvement was the construction of a gun tower in the middle of the battery in 1851. The tower has been restored several years ago and two guns were put on the roof.