There used to be 150 windmills in the Alblasserwaard. Nowadays you will have to make do with only 53 mills, 48 of which are water mills. You will see that the water in the ditches is often much deeper on one side than on the other. When all 150 windmills were still there, they pumped the water one meter higher to the low reservoirs of the Nederwaard and Overwaard. Nowadays, the pumping stations do that. Just past junction 9 you will see the Peilmolen. This mill was located in the deepest part of the innkeeper. When the water got too high and milling had to be done, the miller hung a lamp in the blades, turning the mill into a kind of lighthouse. The signal was passed on by all millers up to Kinderdijk. This is how the millers communicated throughout the Alblasserwaard