Puno is undoubtedly the center of tourism by the Lake Titicaca. You can go visit Uros floating islands and Taquile in Peruvian side. If you visit the Lake from the Bolivian side, there are Isla del Sol and Isla de la Luna. Lake Titicaca is unbelievably huge as it measures 22,400 square miles at an elevation of 12,500 feet. It is an amazing lake itself in such a high elevation. Later in my trip to Bolivia's Uyuni Salt Flat, I was told from the tour guide that Lake Titicaca and the Uyuni Salt Flat were created about the same time when the ocean floor was lifted up and landlocked (not sure if that is true though). The difference is there are constant water supply in the Lake Titicaca from the nearby mountains and it drains its water through a small river while most of the water is gone by evaporation by strong sunlight, while the Uyuni Salt Flat does not have any water supply and draining river and all the water basically evaporated and only salty crust left. Whether its origin is true or not, the Lake Titicaca is surely pristine and beautiful and perfectly blend with the deep blue sky in Andean highlands.