Sea in culture of barbarian invaders and knowledge of geography took a backward step. In the seventh century, Isidore of Seville produced a "wheel map" in which Asia, Africa and Europe were arranged like segments in an orange, separated by the "Mare Mediterranean", "Nilus" and "Tanais" and surrounded by "Oceanus". It was not until the fifteenth century that Ptolemy's maps were used again and Henry the Navigator of Portugal initiated ocean exploration and maritime research. Encouraged by him, Portuguese navigators explored, mapped and charted the west coast of Africa and the Eastern Atlantic and this knowledge prepared the way for the great voyages
Desert Shores, California Desert Shores, California Desert Shores (formerly Fish Springs) is a census-designated place (CDP) in Imperial County, California, US. It is part of the El Centro Metropolitan Statistical Area. The town is located at the western shore of the Salton Sea in the Imperial Valley, within the Colorado Desert ecoregion. It is west-northwest of Calipatria. According to the United States Census Bureau, the CDP has a total area of , all land. The population was 1,104 at the 2010 census, up from 792 in 2000. The 2010 United States Census reported that Desert Shores had a population of 1,104. The population