Muralt walls were invented by R.R.L. de Muralt , esq. who was head of technical service of the Schouwen water authority between 1903 and 1913 . After the storm surge of 1906 de Muralt developed a cheap way to raise dykes without having to widen the dyke 's body . Between 1906 and 1935 around 120 km of muralt walls were put into place , about a third of all Zeelandish coastal dykes at the time . However , during the North Sea flood of 1953 it turned out that they were not adequate . Because of this most Muralt walls were removed during the dyke heightening after 1953
North Sea flood of 1953
North Sea flood of 1953
Muralt Wall