Now only used for spraying water...

The lock Dokkumer Nieuwe Zijlen, whose city's name is due to its name, are the locks (old Dutch: sidelines), which were constructed at the closing of the Dokkumergrootdie in 1729. The lock consists of three locks. Two of them could be used by ships. The third was used only for spraying water in the Lauwerszee. After the closure of the Lauwerszee in 1969, the Dokkumer Nieuwe Zijlen lost its function as sea lice.