Casma-Sechin Culture

The Casma-Sechin culture (c. 3600-200 BC) encompasses a large concentration of prehistoric ruins in the Casma and Sechin river valleys of coastal Peru. Sechin Bajo, with a circular plaza radiocarbon-dated to 3500 BC, may contain the oldest monumental architecture in the Americas. Sechin Alto, a flat-topped pyramid measuring 300x250m and 35m high, was the largest construction in the Americas when built around 1600-1400 BC. Cerro Sechin, discovered in 1937 by Julio C. Tello, features megalithic walls with bas-relief carvings graphically depicting human sacrifice. The size and uniformity of these monuments suggest Sechin Alto served as the administrative center of a polity uniting the valleys under one government.