Lake Titicaca seems more like an ocean than a lake. Bright-green algae blankets beach boulders and fills the air with a musty, seaside smell. Waves lap sand beaches. The intense blue waters, as deep as 270 meters, stretch endlessly in all directions. The only reminders, in fact, that Lake Titicaca is a lake are the impossibly thin air and a backdrop of snow-covered mountains—and the sight of islanders drinking the lake’s clear waters out of their cupped hands.

The best way to experience Lake Titicaca is to leave behind the bustle of Puno and escape to the lake’s placid shores and islands. Here you will find paths bordered by stone walls, a crystal-clear sky, and sweeping views of arid, sun-baked terraces.

The land, shaded in places by groves of eucalyptus, plunges into waters below. On sunny days, the air is perfectly still and the sky blends with the water to form a single expanse of blue. The mood changes quickly, however, when squalls swoop in from the high plateaus, plunging temperatures and whipping the lake into a froth of gray waters. By evening, when the lake is calm again, the sunset appears as a line of fire around a half moon, the curvature of the earth plainly visible.

It is no coincidence that the Inca decided first to conquer this lake, nor that they formed a creation myth around it. The Inca contend that the sun sent his son, Manco Cápac, and the moon sent her daughter, Mamo Ocllo, to emerge from the waters of Lake Titicaca and found the Inca empire.

It is also no coincidence that the Spaniards decided to bequeath this lake and its people directly to the king, and not to a conquistador as was usually the case. For despite its altitude and barren appearance, Lake Titicaca has been a cradle of civilization and a center of wealth. The dense populations of Quechua- and Aymara-speaking people around this lake have a unique place in Peruvian culture because their ways of life go back at least 3,000 years.

By 600 B.C., the Chiripa and Pukara populations were already building temples around the lake, which offered a perfect combination of grasslands for llamas and alpacas, an ample supply of fish, and good growing conditions for potatoes and quinoa. By A.D. 200 the carved, gold-covered stone blocks were being raised on the shores of Lake Titicaca to build Tiwanaku, a city in present-day Bolivia that lasted a thousand years.

The Tiwanaku empire, along with the Ayacucho-based Huarri, would later spread its deities and urban ways of life across Peru, laying the foundation for the Inca empire. The Tiwanaku empire collapsed around A.D. 1000, perhaps because of a drought, and the Lupaca and Colla emerged to build the tombs at Sillustani and other monuments. These proud cultures would become famous for their bloody rebellions against both the Inca and the Spanish.