The Cumbre Mayo is an area of unusual rock formation high in the mountains above Cajamarca. The old Moyobamba Route mule trail passed through here. This is also where Francisco Pizarro's army camped the night before they went down to Cajamarca to meet (and capture) the head of the Incas. It was so cold that some of their horses got frostbite. It can get up to almost 100F/38C during the day here but at night the tempertures can fall to 0F/-18C. The elevation is about 11,500 feet/3,500 meters. One of the most interesting things here is the 3,000 year old irrigation channel (see below).
There is no public transportation to this area so I took a tour. There were about a dozen Peruvian from the coast and me. We walked through the area for about two hours.
Among the formations is this 3,000 year-old irrigation channel. It's about 4 miles/6 kilometers long. They didn't actually farm up here. The channel redirects water that would go down the west side of the mountain over to the east side where it flows into a stream that feeds fields lower down. They made channels through the rock and sometimes little tunnels.