The highest elevation I touched was the Andes mountains overlooking Quito, Ecuador. I travelled from Quito, to Banos, to Guayaquil thru the Andes range to the coast, but I don't know all the exact elevations that I touched. The city Quito is in a valley at elevation 9,200 ft., and I hiked the mountain above that. The mountain is an active volcano, Guagua Pichincha, at 15,692 ft (4784 m). A small earthquake happened while I was there.
I slept on the mountain overnight. In the morning, it was a weird sight. From the mountain I looked down into the valley. The entire huge capital city Quito disappeared under the clouds below me. It was like the whole world went back in time.
