In the Valley of Mexico (c. 1250 CE), there existed numerous city-states, including Chalco, Xochimilco, Tlacopan, Culhuacan, and Azcapotzalco. The most powerful were Culhuacan on the south shore of Lake Texcoco and Azcapotzalco on the west shore. As a result, when the Mexica arrived in the Valley of Mexico as a semi-nomadic tribe, they found most of the area already occupied. In roughly 1248, they first settled on Chapultepec, a hill on the west shore of Lake Texcoco, the site of numerous springs.