The waru waru restoration project began in 1991 in the southern Andean department of Puno, Peru. The aim is to recover a technology, invented by the Tiahuanaco culture, that fell into disuse around 1100 A.D. Archaeological excavations of raised fields demonstrated that farmers began constructing them by 1000 BC. Waru waru, or raised field, agriculture makes it possible to bring into production the low-lying, floodprone, poorly drained lands found all over the Altiplano. The project involves the restoration of earthworks that are central to the technology.