I was on a flight from La Paz to Lima Peru in my favorite aircraft (737) at 30,000 feet. Right over the Andes and I noticed some interesting textures in the mountains far below. I went down and had a look and found an awesome canyon, which I believe is the headwaters of the Amazon River. It was big enough to squeeze my 747-400 through. At the east end there is even a waterfall. Has any one else found this, if not take a look. Here are the co-ordinates S. 12,17.73 W.74,11.60 around 7700 feet.