On this journey Cieza de León had an opportunity to see the Ecuadorian plateau, the western side of the Andes, and the sandy region of the coast, as well as some of the more important ruins of Inca buildings, the ancient roads, and the system of canals designed for irrigation under the Inca régime. He moreover witnessed the overthrow of Gonzalo Pizarro and was present at the execution of both Pizarro and Carbajal. Later he went to Cuzco. At this time Inca Garcilaso de la Vega, then eleven years of age, was at school in that city, and the two persons who were destined to become pre-eminent among the early historians of Peru were here either completing or beginning their training for the literary undertakings that were before them. Cieza de León had prepared himself for his work in the camp, and in extensive journeys over the country he was to describe. Garcilaso de la Vega was receiving such tuition as the Church of his day was accustomed to sanction. He was then studying Latin under the instruction of Canon Cuellar. In 1549 Cieza de León visited the province of Charcas, and in the ninety-fifth chapter of his Travels he wrote: “I went to see the cities in that region for which purpose the President Gasca gave me letters of introduction to the corregidores, that I might learn all that was worthy of notice.”[24] He passed along the eastern shore of Lake Titicaca, and visited the mines of Porco and Potosí. From Potosí he went to Arequipa, and thence by way of the coast to Lima. At Lima he completed the notes of his journey in September, 1550. From his observations he gives the following account of the fair of Potosí: [Sidenote: The fair at Potosí] [Sidenote: Trading at the fair]