Some proposals would have put the altar on es-Sakhra, but then es-Sakhra would have disappeared completely below it, as es-Sakhra is smaller than the altar. According to Middot 3.1, the altar was 32 cubits (55 feet, or 16.8 meters) square. Another problem with placing the altar over es-Sakhra is that the well-known cave that lies below es-Sakhra, which was supposed to have drained off the blood to the Kidron Valley, would be in the wrong place, as, according to Middot 3.2, this original drain was located at the southwest corner of the altar, while the cave is on the southeast corner.