For 250 years, hundreds of Manila galleons traveled from present-day Mexico to the Philippines, with their route taking them south of the Hawaiian Islands. And yet, no historical records of any contact between the two cultures exist. British historian Henry Kamen maintains that the Spanish did not have the ability to properly explore the Pacific Ocean, and were not capable of finding the islands which lay at a latitude 20° north of the westbound galleon route and its currents. However, Spanish activity in the Pacific was paramount until the late 18th century. Spanish expeditions discovered Guam, the Marianas, the Carolines and the Philippines in the North Pacific, as well as Tuvalu, the Marquesas, the Solomon Islands and New Guinea in the South Pacific. Spanish navigators also discovered the Pitcairn and Vanuatu archipelagos during their search for Terra Australis in the 17th century.