We just returned from Cancun, where we toured the ruins of Tulum. The maya apparently had folded books, which out of thousands only 3 remain. To see them, you have to travel to Madrid, Paris or Dresden. Apparently the rest were burned by Spanish when they arrived in late 1580. Somehow I was overwhelmed with a huge sense of loss when I heard this. Knowledge from around 3000 bc to 1580 or so just burned.