The Caribbean Sea is a tropical sea in the Western Hemisphere, bounded by Mexico and Central America to the west, the Greater Antilles to the north, and South America to the south. It is one of the largest seas in the world, covering about 2.7 million square kilometers. The sea is characterized by its crystal-clear waters, which are low in nutrients but house approximately 9% of the world's coral reefs, including the Mesoamerican Barrier Reef. Geologically, the Caribbean Plate is highly active, resulting in the volcanic islands of the Lesser Antilles and frequent seismic activity. Historically, the sea was the center of European colonial expansion and piracy. Today, it is a global tourism powerhouse, though it is increasingly vulnerable to rising sea temperatures, coral bleaching, and more intense hurricane seasons driven by climate change.