Middle Spotted Woodpecker
In the far south you can find the highest point of the country, the Pietersberg rising 171meters (LOL)! In the quarry breeds Eagle Owl and in the nearby forests you can find Black and Middle Spotted Woodpecker.
The best time to visit is early spring when there aren't many leaves on the trees. This is the time woodpeckers and the owls are calling and easiest to see. In the streams you can find Grey Wagtail and with luck a Dipper.
When there's a wind from the east it's good to keep an eye on the sky for migrating Cranes and Red Kites. In the fields there are special reserves for buntings where you can find Corn Bunting and Yellowhammer and other seed eaters. These flocks are targeted by Hen Harrier and Sparrowhawks.
For those who are interested in more then birds this area has some special butter- and dragonflies and specialized plants.