How ancient stone kitchens preserve food secrets

The mortar, pestle and cutting board in your kitchen are modern versions of manos and metates—ancient cooking implements found in archaeological sites around the world. A mano is a hand-held stone tool used with a metate to grind and pulverize food materials from plants and animals. The metate is a large, flat piece of stone or a depression ground into a bedrock surface. These bedrock metates, also known as open-air metates, are particularly common at archaeological sites, with the oldest dating as far back as 15,500 years.