Thinly slice the cucumber with a cheese slicer or mandolin. If you don´t have either, use a sharp knife to make slices.
Lay cucumber slices as a thin layer on a plate. Sprinkle some salt over them. Repeat the process until you have layered up all cucumber.
Place another plate on top of the slices and add some weight on top, for example, canned goods or a heavy stone. Let them rest for at least 15 minutes.
Meanwhile, combine the water, vinegar, and sugar in a saucepan. Warm until the sugar dissolves. (does not need to boil).
Drain off the liquid that has come out of the cucumber slices.
Layer the slices with dill and pepper in a glass jar. Pour over the pickling liquid.
Refrigerate at least 1 hour before serving to allow flavors to develop.