It was situated in a crater of a extinct volcano, and was about 200 yards (? meters) in diameter. The volcano itself was somewhere in the hills of the northeastern area of the House of Tezca.
If someone sat at the western edge of the lake at sunrise, then when the sunlight hits the silver liquid, then the watcher would be granted a vision. If the watcher had pure intentions, then the vision would prove true and aid the watcher. If the person had false or selfish reasons, then the vision would provide false information. Beyond that, little was known about the nature of the visions. In addition, touching the liquid, even by way of an object, would immediately teleport the person to a random location in the surrounding desert.