Baodun culture thrived 2700-1700 BC on Chengdu Plain in Sichuan China. Ten settlements straddle Min River with unique pebble-covered walls. Baodun type site is oldest and largest with inner wall 66 ha and outer 245 ha. Building Baodun walls took 222-666 person-years at 1-3 m³ per person per day. Yufu site has inner wall 25 ha and outer 40 ha. Mangcheng has inner 7.2 ha and outer 10.5 ha walls. Gucheng wall encloses 30.4 ha. Zizhu and Shuanghe have double walls. Inhabitants used wattle and daub houses. Baodun yields earliest rice and foxtail millet evidence in southwest China. Rice dominated over foxtail millet at Baodun. Paddy rice weeds found at Baodun. Job's tears, Vicia, Vigna, beefsteak plant, Crataegus remains at Baodun. Rice also at Mangcheng. Radiocarbon dates 2467 BC and 1993 BC from Bianduishan. Baodun pottery similar to Sanxingdui. Baodun has largest walled Neolithic area in China.