Westdeutscher Rundfunk is a public broadcaster headquartered in Cologne (Köln), which serves the German Federal State of North Rhine-Westphalia. It consists of six radio networks and a television network. It was formed in 1956 when the Nordwestdeutscher Rundfunk split into the Norddeutscher Rundfunk and Westdeutscher Rundfunk. You can find their website here http://www1.wdr.de/themen/index.html
We could regularly hear their medium wave outlets in southern Germany where we lived. We heard their FM outlets during a visit to Northern Germany. Their 1593 kHz outlet was widely heard throughout Europe and other continents. They sent the QSL cards below for my reception reports. Their QSLs for 720 and 1593 kHz are among my favorites in my collection.
(Scroll down to see the QSL cards WDR sent for my reports.)