Scientists have dated burial mounds found along Florida’s western coast at more than 10,000 years old. There were about 350,000 Native Americans living in the Florida region when the first European explorers arrived. These Indians belonged to five main groups: the Calusa, the Tequesta, the Ais, the Timucua, and the Apalachee. Spanish conquistador Ponce de León reached Florida in 1513 while searching for the mythical island of Bimini, said to be the site of the Fountain of Youth. Claiming the region for Spain, he named the area ” La Florida”, possibly in honor of Pascua Florida, Spanish for the Easter season. In 1521, León returned to Florida to start a colony, but died from wounds he received in a battle with Indians. Pánfilo de Narváez led an expedition of 400 men to Florida in a quest to find gold, though Narváez and most of his men were killed at sea. Hernando de Soto of Spain arrived in the Tampa Bay area in 1539. He traveled beyond Florida, becoming the first European to reach the Mississippi River.