Yesterday I spent the afternoon in Hasseler Forst, a local park and birding spot here in Düsseldorf. I was able to find about 35 species while playing around with my kids--including Middle Spotted Woodpecker (my new favorite woodpecker!). A series of lakes is nearby at Elbseen, which held lots of waterbirds including Tufted Duck, Great Crested Grebe, and Eurasian Coot, as well as a Grey Heron rookery.
To get to Hassler Forst, take a bus to the Hassels Kirche stop, and take the road and path near the church back to the park. You first go over a highway crossing, and then in about a quarter mile you hit an area with conifers on both sides that is supposed to be good for Goldcrest and Firecrest (I only got the Goldcrest on my short visit).
Beyond the conifers is a train track, and take the path to the right through some oaks, where the Middle Spotted Woodpeckers are found. Also saw Great Spotted Woodpecker and Green Woodpecker here.
At the end of this path is a playground (for the kids), and you can take the path to the left to go under the train tracks to Elbseen. From there take the path to the right to get the best views of the lakes. About a half mile down this path is a viewing tower.
A great place to bird and I look forward to getting back there soon! Thanks to local birder Klaus Böhm for the directions!