Aymara woman walking on Isla del Sol (Island Of The Sun), Lake Titicaca, Bolivia. Isla del Sol is an island in the southern part of Lake Titicaca. It is part of the modern Plurinational State of Bolivia. Geographically, the terrain is harsh; it is a rocky, hilly island. There are no motor vehicles or paved roads on the island. The main economic activity of the approximately 800 families on the island is farming, with fishing and tourism augmenting the subsistence economy. Of the several villages, Yumani and Cha'llapampa are the largest.There are over 80 ruins on the island. Most of these date to the Inca period circa the 15h century AD. Archaeologists have discovered evidence that people lived on the island as far back as the third millennium BCE. Many hills on the island contain agricultural terraces, which adapt steep and rocky terrain to agriculture. Among the ruins on the island are the Sacred Rock, a labyrinth-like building called Chicana, Kasa Pata, and Pilco Kaima. In the religion of the Incas, it was believed that the sun god was born here.