The capital and largest city of Newfoundland and Labrador, St John's is located on the eastern side of the AVALON PENINSULA of southeast Newfoundland. Its landlocked harbour is approached through a long, narrow channel and is protected by the high hills on which the city is built. The origin of the name St John's is not known, but its use appears on a Portuguese map by Pedro Rienel (1516-20) as "Rio de San Johem" and later, in a 1527 letter by the English seaman John Rut, as the "Haven of St John's." According to popular folklore, however, the city takes its name from the feast of Saint John the Baptist and the discovery of Newfoundland for England on 24 June 1497 by the Italian discoverer Giovanni Caboto (John CABOT).