side the Portuguese and later the Dutch built a regular trade from the East Indies to Japan. On the American side Spanish power stretched thousands of miles from Mexico to Chile. The vast central Pacific was visited only by the Manila galleons and an occasional explorer. The south Pacific was first crossed by Spanish expeditions in the 16th century who discovered many islands including Tuvalu, the Marquesas, the Cook Islands, the Solomon Islands, and the Admiralty Islands, and later the Pitcairn and Vanuatu archipelagos. The Pacific recognized Europeans knew that there was a vast ocean to the west, and the Chinese knew that there was one to the east. Learned Europeans thought that the world was round and that the two oceans were one. In 1492, Columbus sailed west to what he thought was Asia. When Pedro Álvares Cabral, en route to Asia via the Atlantic and the Indian oceans, reached Brazil, in 1500, the true extent of the Americas began to become known. The Martin Waldseemüller map of 1507 was the first to show the Americas separating two distinct oceans. This guess was confirmed in 1513, when Balboa crossed Panama and found salt water. The Magellan expedition of 1519-22 proved that there was one continuous ocean from the Americas to Asia. The Diogo Ribeiro map of 1529 was the first to show the Pacific at about its proper size. The coast of Asia The Portuguese reached India in 1498, conquered Malacca in 1511 and in 1512 António de Abreu and Francisco Serrão reached the Spice Islands. In May 1513 Jorge Álvares reached southern China and in the same year Balboa crossed Panama. In 1525 Diogo da Rocha and Gomes de Sequeira reached the Caroline Islands, and Jorge de Menezes in 1526-27 landed on the Islands of Don Jorge de Menezes, in the northwest coast of New Guinea (now part of Indonesia), and named the region Ilhas dos Papuas and is thus credited with the European discovery of Papua. In 1542 Fernão Mendes Pinto reached Japan. From about 1543 until 1614, the Portuguese monopolize the trade between China and Japan, through the nanban trade. In 1589, João da Gama reached Hokkaido and possibly sighted the Kuril islands, crossing the Pacific further north of the routes usually taken until then. The land that he eventually discovered northeast of Japan, has since become a matter of legend and controversy. One hundred years