A few weeks ago I went to the Amsterdamse waterleidingduinen, near Amsterdam. 40 km pure nature, full with foxes, deers and sheep. You will not believe how close it is near Amsterdam. You can get there in like 20 minutes.
You only pay €1,50 entrance for a whole day. You will find some interesting landscapes and birds. Here and there you’ll find a bunker from WWII. Amazing place to start photography, to write, chill out or just walk around. In the weekend it can be a bit busy, you should visit in the weekdays, especialy in the morning you’ll be alone and you’ll definitely see foxes and such. You can find more information on their website.