Pre-Columbian rafts voyaged as far as Mexico and introduced metallurgy to the civilizations of that country. Some scholars and adventurers of the 20th and 21st century have asserted that the rafts and their crews journeyed thousands of miles across the Pacific to Polynesia, most notably Thor Heyerdahl who reached Polynesia on the Kon-Tiki raft. Several other people and groups have also built rafts based on prehistoric models and undertaken trans-Pacific voyages. Balsa is the Spanish word for raft. The use of rafts for commerce on the coasts of Peru and Ecuador, from northern Chile to southern Colombia, continued until the late 19th
Thor Heyerdahl great diversity in race, nationality, religion and political viewpoint in order to demonstrate that at least on their own little floating island, people could cooperate and live peacefully. Additionally, the expedition took samples of marine pollution and presented their report to the United Nations. Heyerdahl built yet another reed boat, "Tigris", which was intended to demonstrate that trade and migration could have linked Mesopotamia with the Indus Valley Civilization in what is now Pakistan and western India. Tigris was built in Iraq and sailed with its international crew through the Persian Gulf to Pakistan and made its way into the