Location map North Rhine-Westphalia, Germany. Geographic limits of the map:
Own work, based on (not all layers may be visible or included):

File:North rhine w template 2.svg by TUBS (for borders)
Bezirksregierung Köln: Nordrhein-Westfalen in Zahlen und Karten (for rivers)
Ministerium für Umwelt und Naturschutz, Landwirtschaft und Verbraucherschutz des Landes Nordrhein-Westfalen: Bäche/Flüsse/Seen (for rivers)
Landesumweltamt Nordrhein-Westfalen: Gewässergüte in Nordrhein-Westfalen (for rivers)
File:Netherlands Limburg location map.svg, by Erik Frohne (for rivers and borders)
File:Netherlands Overijssel location map.svg, by Erik Frohne (for rivers and borders)
File:Netherlands Gelderland location map.svg, by Erik Frohne (for rivers and borders)
Hessisches Landesamt für Umwelt und Geologie: Wasserrahmenrichtlinie in Hessen (for rivers and borders)
File:Municipalities in Rhineland-Palatinate.svg by TUBS (for rivers and borders)
For populated areas, either:
Bezirksregierung Köln Übersichtskarte NRW 1:500.000 für Nordrhein-Westfalen  (may be substituted by www.maps-for-free data in later versions) or
www.maps-for-free.com
Wasser- und Schifffahrtsverwaltung des Bundes: Bundeswasserstraßenkarte DBWK1000 (for channels)
For topography and hill shades, either:
www.maps-for-free.com (like in File:North Rhine-Westphalia Topography 02.png by TUBS) (may be substituted by SRTM data in later versions) or
NGA's and NASA's SRTM3 data provided to me by user Alexrk2, much like applied in File:North Rhine-Westphalia relief location map.jpg
Alexrk2 also helped me with corrections of the projection of my maps thus becoming a equirectangular projection maps. Alexrk2 provided me this help via email but the application of his/her corrections werde first made public by uploading the file File:North Rhine-Westphalia relief location map.jpgOnly to compare some issues:

Ministerium für Umwelt und Naturschutz, Landwirtschaft und Verbraucherschutz des Landes Nordrhein-Westfalen: Fließgewässer, Kanäle und Seen in NRW
TUBS