Well, if you want to know when they disappeared, most of the great Mayan cities were abandoned near 900 A.D. Nobody knows why! By 1450 all major cities were completely abandoned, religion became less and less important just like art and architecture. While some people think more time was spent at war, and the few people that lived, took refuge in the countryside. But like we said before, no one knows for sure. They might not have disappeared because of a war. They could have just vanished out of thin air!