This process was first used on a large scale by the Pucara (–AD 300) peoples to the south in Lake Titicaca and later in the city of Tiwanaku (–1100) in what is now Bolivia. The rocks were sculpted to fit together exactly by repeatedly lowering a rock onto another and carving away any sections on the lower rock where the dust was compressed. The tight fit and the concavity on the lower rocks made them extraordinarily stable, despite the ongoing challenge of earthquakes and volcanic activity.
This process was first used on a large scale by the Pucara (–AD 300) peoples to the south in Lake Titicaca and later in the city of Tiwanaku (–1100) in what is now Bolivia. The rocks were sculpted to fit together exactly by repeatedly lowering a rock onto another and carving away any sections on the lower rock where the dust was compressed. The tight fit and the concavity on the lower rocks made them extraordinarily stable, despite the ongoing challenge of earthquakes and volcanic activity.