I have discussed places in many provinces in the Netherlands, but not yet a beautiful spot located in the province I live in: Drenthe!
The Blue Lake is a sand extraction site of the brick factory. After sand dredgers did their work for many years, without interruption, the Blue Lake was created. Glauconite, a mineral with a dark green color, occurs in the sand. This creates the blue-green color of the lake.
It is a 2 hour trip from Amsterdam to reach The Blue Lake (het blauwe meer).
Update
The Blue Lake was one of the first things I visited when I went back to NL. I can tell you that it is absolutely beautiful. It doesn’t feel like you are in the Netherlands. I did not have to pay to enter, but I saw that you will have to pay 3 euros after the month of May.
There’s even a fun swing to take some cool pictures and if you walk further, you can find another lake, which is even bluer. I don’t think that is natural, but for sure nice to see.