Hike down from the Legion of Honor Museum along the Lands End trail and go right off the trail. I think we were about here: http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=37.787937,+-122.505820&aq=&sll=37.799001,-122.517815&sspn=0.052561,0.079651&ie=UTF8&ll=37.793304,-122.498846&spn=0.052565,0.079651&t=h&z=14