Final answer:
Spanish explorers set out from the Caribbean to explore and conquer the Pacific coast of South America, led by conquistadors such as Hernán Cortés and Francisco Pizarro after Christopher Columbus's initial voyages.
Step-by-step explanation:
The point of departure for the Spanish to explore and conquer the Pacific coast of South America was from the Caribbean, where they had established some of the first European settlements in the Americas. Notably, Christopher Columbus, who left from Spain and arrived in the Caribbean in 1492, laid the groundwork for subsequent expeditions. Eventually, conquistadors like Hernán Cortés conquered the Aztec Empire and Francisco Pizarro took over the Inca Empire, both traveling from these early Caribbean settlements to embark on their respective conquests of the Americas.