Buy this book on Amazon: A Short History of the World
Over on the other side of the world, a civilisation of its own developed in Central America: that of the Olmecs. We know less about the Olmecs than we know about the major civilisations that developed in Asia as they left very few written records before all traces ceased in circa 400 BC for reasons unknown (although very possibly due to environmental change). We know that they had a calendar, carved gigantic stone heads, built large pyramid-like structures and that they traded extensively. Bloodletting and human sacrifice were a part of their religious life and the rituals and beliefs of the Olmecs formed the basis of the rituals and beliefs of the civilisations that would inhabit the area after them, including those of the Mayans and the Aztecs.