The region of Puno played a very important role in pre-Inca and Inca times. According to the legend, Manco Capac, the first Inca, and his wife Mama Ocllo emerged from Lake Titicaca instructed by their father, the Sun, to establish the Tahuantinsuyo Empire. Puno's main attraction is Lake Titicaca: Situated at 3,809 meters above sea level ( 12,379 ft ), Lake Titicaca is the highest navigable lake in the world, with a length of 120 miles ( 194 kilometers ) and an average width of 40 miles ( 65 kilometers ). Its depth exceeds 81 feet ( 25 meters ) in places, and its colors range from deep blue to pale green. An extraordinary variety of wildlife makes its home by the lake, including flamingos, ducks, trout and local fish such as the suche and carachi. The totora reed, which grows all over the lake serves both as food (for people and animals), and building materials (for homes and rafts).
There a few different ways to get there. Usually the best time to go is during the dry season from April to November.
To check out a few photos, take a look at:
http://www.peruforless.com/gallery/photos-peru-puno.php