Schiermonnikoog used to have 2 lighthouses, and both were built in 1853. The white one on the picture (also known as the south tower) is located on a high spot in the village. When the other one (the north tower) was installed with a rotating lense in 1911 it wasn't necessary anymore for the island to have 2 lighthouses for landmarks. From 1950 until 1992 it was then in use as a water tower. Nowadays Telecom Services use it for their antennas.
I posted a photo of the red lighthouse (the north tower) a while ago, if you would like to see it click HERE.