The Water that is pumped by the mill has a exit called "waterloop". It houses a door to keep the water on the high side of the mill out (like a horizontal sluice door). Otherwise the water would run back into the polder and that's something we do not want. On top of the waterloop there's decking so you can walk on it.
Making the "waterloop"
Starting with 3.6 mm thick lumber
Cutting it to size
Adding metal strips to make the hinges from
Soldering the hinges in place
a closed door.
Because gluing end grain to end grain is not a good idea I made some dovetail mortises to connect the parts together
Assembled together
Gluing the decking together with some spacer between the planks
The end result