The Baja California Peninsula is a peninsula in Northwestern Mexico. It separates the Pacific Ocean from the Gulf of California. The peninsula extends 1,247 km (775 miles) from Mexicali, Baja California in the north to Cabo San Lucas, Baja California Sur in the south. The land of California existed as a myth among European explorers before it was discovered. The earliest known mention of the idea of California was in the 1510 romance novel Las Sergas de Esplandián by Spanish author Garci Rodríguez de Montalvo. The book described the Island of California as being west of the Indies, "very close to the side of the Terrestrial Paradise; and it is peopled by black women, without any man among them, for they live in the manner of Amazons." Following Hernán Cortés' conquest of Mexico, the lure of an earthly paradise as well as the search for the fabled Strait of Anián, helped motivate him to send several expeditions to the west coast of New Spain in the 1530s and early 1540s. Its first expedition reached the Gulf of California and California, and proved the Island of California was in fact a peninsula. Nevertheless, the idea of the island persisted for well over a century and was included in many maps. The Spaniards gave the name Las Californias to the peninsula and lands to the north, including both Baja California and Alta California, the region that became parts of the present-day U.S. states of California, Nevada, Utah, Arizona, and parts of Colorado and Wyoming.