Holy Grail Temple is a 6,711-foot summit in the Grand Canyon’s Shinumo Amphitheater, rising more than 4,500 feet above the Colorado River and draining south into Shinumo Creek. Its name became part of a nearby Arthurian theme after Virginia Dox had first called it Bass Tomb in 1891 for guide William Wallace Bass; the U.S. Geological Survey proposed Holy Grail Temple, and the U.S. Board on Geographic Names adopted it in 1908. Bass remained linked to the area, and his ashes were scattered atop the summit in 1933. First climbed in 1977, the peak also reveals a striking sequence of Grand Canyon rock layers from Coconino Sandstone downward.