Panama is a country on the isthmus linking Central and South America. The man-made Panama Canal cuts through its center, linking the Atlantic and Pacific oceans to create an essential shipping route. In the capital, Panama City, modern skyscrapers, casinos and nightclubs contrast with colonial buildings in the Casco Viejo district and the rainforest of Natural Metropolitan Park. The balboa (sign: B/.; ISO 4217: PAB) is, along with the United States dollar, one of the official currencies of Panama. It is named in honor of the Spanish explorer/conquistador Vasco Núñez de Balboa. The balboa is subdivided into 100 centésimos. In 1966, Panama followed the U.S. in changing the composition of their silver coins, with copper-nickel clad 1⁄10 and 1⁄4 balboa, and.400 fineness 1⁄2 balboa. 1 balboa coins, at.900 fineness silver, were issued that year for the first time since 1947. In 1973, copper-nickel clad 1⁄2 balboa coins were introduced. 1973 also saw the revival of the 2 1⁄2centésimos coin, which had a size similar to that of the U.S. half dime, but these were discontinued two years later due to lack of popular demand. In 1983, 1 centésimo coins followed their U.S. counterpart by switching from copper to copper plated zinc. Further issues of the 1 balboa coins have been made since 1982 in copper-nickel without reducing the size. Modern 1 and 5 centésimos and 1⁄10, 1⁄4, and 1⁄2 balboa coins are the same weight, dimensions, and composition as the U.S. cent, nickel, dime, quarter, and half-dollar, respectively. In 2011, new 1 and 2 balboa bimetallic coins were issued. In addition to the circulating issues, commemorative coins with denominations of 5, 10, 20, 50, 75, 100, 150, 200, and 500 balboas have been issued.