to some of the earliest pottery-making, such as the Monagrillo culture dating to about 2500–1700 BC; this culture evolved into significant populations best known for spectacular burial sites (dating to c. 500–900 AD) and polychrome pottery of the Coclé style. Each of these cultures rose, flourished, and was then conquered by a more militarily developed culture. While not all of these civilizations had large settlements along the coast of the Pacific Ocean, their influence extended to the Pacific coast. Regional communications in ancient Mesoamerica—and especially along the west coast—have been the subject of considerable research. There is evidence of trade routes starting as far north as the Mexico Central Plateau, and going down to the Pacific coast. These trade routes and cultural contacts then went on as far as Central America. These networks operated along the west coast with various interruptions from pre-Olmec times and up to the Late Classical Period (600–900 CE). European arrival (1513–1750) In 1513, Spanish explorers were the first Europeans to reach the west coast of North America, on the Pacific coast of the Panama isthmus. From the point of view of European powers in the age of sailing ships, the west coast of North America was among the most distant places in the world. The arduous journey around Cape Horn at the tip of South America and then north meant nine to twelve months of dangerous sailing. These practical difficulties discouraged all but the Spanish Empire from making regular visits and establishing settlements and ports until the second half of the 18th century—some 200 years after Europeans first reached the east coast of North America. Spanish explorers and conquistadors Explorers flying the flag of Spain reached the New World beginning in 1492 with the discovery of the Americas by Christopher Columbus. Spanish expeditions colonized and explored vast areas in North and South America following the grants of the Pope (contained in the 1493 papal bull Inter caetera) and rights contained in the 1494 Treaty of Tordesillas and 1529 Treaty of Zaragoza. These formal acts gave Spain the exclusive rights to colonize the entire Western Hemisphere (excluding eastern Brazil), including all of the west coast of North America. The first European expedition to actually reach the west coast was led by the Spaniard Vasco Núñez de Balboa, who reached the Pacific coast of Panama in 1513. In an act of enduring historical importance, Balboa claimed the