Christopher Columbus
He was Italian, of course, but he sailed for Spain.

Vasco Nunez de Balboa
He was the first European to see the Pacific Ocean

Juan Ponce de Leon
Most famous for his search for the Fountain of Youth

Ferdinand Magellan
He was from Portugal but sailed for Spain.

Francisco Pizarro
Conqueror of the Inca Empire

Hernando Cortez
Conqueror of the Aztec Empire

Hernando de Soto
Known for "discovering" the Mississippi River

Francisco Vaszquez de Coronado
Famously explored the American Southwest