The Tiwanaku Polity (Spanish: Tiahuanaco or Tiahuanacu) was a Pre-Columbian polity in western Bolivia based in the southern Lake Titicaca Basin. Tiwanaku was one of the most significant Andean civilizations. Its influence extended into present-day Peru and Chile and lasted from around 600 to 1000 AD. Its capital was the monumental city of Tiwanaku, located at the center of the polity's core area in the southern Lake Titicaca Basin. This area has clear evidence for large-scale agricultural production on raised fields that probably supported the urban population of the capital. Researchers debate whether these fields were administered by a bureaucratic state (top-down) or through a federation of communities with local autonomy (bottom-up; see review of debate in Janusek 2004:57-73). Tiwanaku