Gardening technology progresses, leading to the development of agriculture and the drawn-out transition to settled village life from hunter-gatherer lifeways. Corn and techniques for its cultivation, undoubtedly introduced from Mexico, are present in the Southwest. Corn becomes the most significant food crop in native North America, and the presence of pottery leads to major changes in the storing and transportation of food. Plazas and large earthen mounds are constructed in the lower Mississippi River valley at Poverty Point in Louisiana. In the eastern and western Arctic, small, delicately made stone tools are produced.