Latin America refers to the regions of Mexico, Central America, South America, and the Caribbean islands where Spanish and Portuguese are predominantly spoken. The climate varies from tropical in Central America to temperate in southern South America and northern Mexico. Seasons are reversed in the Southern Hemisphere. Major physical features include the Andes Mountains, Sierra Madre Mountains, Caribbean islands, Galapagos Islands, and rainforests like the Amazon. Coastal deserts like the Atacama in Chile form due to the rain shadow effect of the Andes blocking moisture. Rivers include the Amazon, and physical geography has impacted population patterns with urbanization along coasts and formation of megacities.