Over 60% of the land in Brazil is covered by the dense Amazon Rainforest. For this reason, three-quarters of Brazilians live in urban areas. The largest urban area of Brazil, by population, is Sao Paulo. The city has a population of over 20 million, making it the second largest urban area in the Americas. It is larger than any of the cities of the United States and is the tenth largest city in the entire world. Sao Paulo is also the economic capital of the largest economy of Latin America and the Southern Hemisphere. The city has six of the top ten tallest buildings in Brazil and eleven of the top fifteen. It is considered a cosmopolitan area with a rich ethnic history.