The titled refers to the place where Rembrandt used to paint: the river The Amstel near Amsterdam. I don't know if that mill already existed in Rembrandt's time but does that really matter?
I wanted to create a postcard which you can buy in some artistic shops. The colourization turned out to be pretty easy however the picture was far too clean (had too little noise in it) to let people think of an old picture. Therefore I played a little with the levels function until I got the result which you can see.