Tiahuannacu (Tikwanaku) Almost a millenium before the Inca forged their empire, this area emerged as a major center of political, economic, and religious life on the shore of Lake Titicaca. Many of the presicely carved H stones vital to the empire were suddenly strewn about. What caused this, how were the stones carved, and what was their purpose? This site is an in depth description of this empire. Fasinating!