You're thinking of the Aztecs, who had some of the most well organized, cleanest cities in the world, despite brutal sacrifices which replaced death in warfare. It's an odd paradox noted by the Spanish. It's like hearing how the Vikings cleaned themselves obsessively before viciously going to raiding campaigns.

The Maya, despite the Spanish, still exist today. You can even eat their foods, like Poc Chuuc, Xec salad, Tikin Xic, Cochinitas Pibil, Sikil Pak, etc.