Tom, this is the “Dithmarscher Landesdenkmal”, a monument commemorating a battle between regional farmers and a Danish-Holstein army on February 17th, 1500. The peasants from Dithmarschen were victorious and able to resist submission.
The battle field near Hemmingstedt is called “Dusenddüfelswarf”, which might be translated to something like “hill of a thousand devils”. This monument is located approximately one kilometre from my home.
See my website http://www.berghofer.com for more photos if you are interested and curious.