The Inca Empire was located in the Andes Mountains and Pacific coast of South America, with its capital at Cuzco in present-day Peru. The Inca had a polytheistic religion tied to nature and the sun god Inti. The Sapa Inca, or emperor, had absolute power as both political and religious leader. The Inca built an extensive road network and developed advanced agricultural techniques, but disease and military conflict with Spanish conquistadors led by Francisco Pizarro ultimately brought about the decline and fall of the Inca Empire in the 16th century.