Found this medal in my front yard this morning (in Kentucky if that makes any difference). Who were these given to? How many were given out? What was the Holzminden internment camp? Here are some pictures of the medal in question: http://imgur.com/oytzuef http://imgur.com/qFrFJNF
Holzminden Internment Camp was a camp for foreign nationals within Germany during WWI; French, Belgian, Polish, even some British civilians were interned there during the war. As to why the medal was given out, it could be a commemorative piece; beyond that I'm afraid I can't help you.