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.