Garo was a monthly manga anthology magazine in Japan, founded in 1964 by Katsuichi Nagai. It specialized in alternative and avant-garde manga. Here's a collection of over 50 of the front covers...for more info visit http://en.wikipedia.org/wiki/Garo_(magazine)
Source:
The Three Steps Over Japan blog is a real labour of love, all the Garo magazines have been archived, scanned and reviewed by TSOTE, really good http://threestepsoverjapan.blogspot.com/
http://www.tcj.com/international/garo-1992/
http://vintageninja.net/?p=550