Help researching "Big Mushroom"

Well I'm thinking about doing a map on either of the defensive positions nicknamed "Big Mushroom" or "Little Mushroom." I found out about these while looking at this map.



http://ift.tt/1IPar2f



However, I can't seem to find just about any photos or descriptions of either positions to model the map after. I was wondering if any of you know more about these mushrooms. Any help is appreciated. :)