It's where the Mosel meets the Rhine, in Koblenz. Known locally as "Deutches Eck". There's a statue of Kaiser Bill there. Having been sent 'direct to' it loads of times in the air it was a pleasure to be there on terra firma yesterday!
Yes, that's the German Corner (Deutsches Eck) on the ground, but don't fly there when receiving a direct to the german corner. ATC will expect you to track to KRH/270/12, as stated correctly by The Real Slim Shady.