Adam-ondi-Ahman
Chapman Duncan left the following account of the altar at Spring Hill. "I think the next day, he said to these present: Hyrum Smith, Bishop Vincent Knight, myself and two or three others, "Get me a spade and I will show you the altar that Adam offered sacrifice on." I believe this was the only time Joseph was in Ondi-Ahman. We went about forty rods north of my house. He placed the spade with care, placed his foot on it. When he took out the shovelful of dirt, it barred the stone. The dirt was two inches deep on the stone I reckon. About four feet or more was disclosed. He did not dig to the bottom of the three layers of good masonry well put up wall. The stone looked more dressed like stone nice joints, ten inches thick, 18 inches long or more. We came back down the slope, perhaps 15 rods on the level. The prophet stopped and remarked this place where we stood was the place where Adam, gathered his posterity and blessed them, and predicted that should come to pass to later generations." [Chapman Duncan, Autobiography, BYU, HBLL, http://www.boap.org/LDS/Early-Saints/CDuncan.html]
Heber C. Kimball recalled, "While there we laid out a city on a high elevated piece of land, and set the stakes for the four corners of a temple block, which was dedicated, Brother Brigham Young being mouth; there were from three to five hundred men present on the occasion, under arms. This elevated spot was probably from two hundred and fifty to five hundred feet above the level of Grand River, so that one could look east, west, north and south, as far as the eye could reach; it was one of the most beautiful places I ever beheld. The Prophet Joseph called upon Brigham, myself and others, saying, "Brethren, come go along with me, and I will show you something." He led us a short distance to a place where were the ruins of three altars built of stone, one above the other, and one standing a little back of the other, like unto the pulpits in the Kirtland Temple, representing the order of three grades of Priesthood; "There," said Joseph, "is the place where Adam offered up sacrifice after he was cast out of the garden." The altar stood at the highest point of the bluff." (Orson F. Whitney, Life of Heber C. Kimball (Salt Lake City: Stevens and Wallis, 2nd ed. 1945), pp. 208-209.)