Latin America's diverse physical geography includes mountain ranges, rivers, deserts, and seas. The Sierra Madre mountains dominate Mexico and Central America. Central America is an isthmus connecting North and South America, with many volcanoes. The Panama Canal crosses the isthmus. The Caribbean islands vary in size from coral reefs to larger islands with volcanic peaks. The towering Andes mountains run along the western coast of South America. Major physical features also include the Amazon rainforest, the Atacama Desert in Chile, and the Amazon and other rivers.