The Western Hemisphere is the half of Earth that lies west of the Prime Meridian and east of the 180th meridian. It includes North and South America and the surrounding waters. Some geographers use 20° W and the diametrically opposed 160° E as boundaries. According to this scheme, the Western Hemisphere includes the Americas and portions of Africa, Europe, Antarctica, and Asia.
The Western Hemisphere is known for its diverse geography, encompassing a wide range of climates from polar to tropical zones. Key features include the Rocky Mountains, stretching 3,000 miles through Canada and the USA, and the Amazon rainforest, Earth's largest, containing the Amazon River. Major cities in the Western Hemisphere include New York City, Mexico City, and Buenos Aires. The highest mountain in the Western Hemisphere is Aconcagua, in the Andes of Argentina, which stands at 6,960.8 meters (22,837 feet). The CN Tower in Toronto is the tallest freestanding structure, and One World Trade Center in New York City is the tallest building.