Bogotá is the largest city in Colombia and one of the biggest of Latin America. With its many universities and libraries, Bogotá has become known as "The Athens of South America". Bogotá has 20 about districts, forming a network of neighborhoods. Higher income areas tend to be located to the north and north-east, close to the foothills of the Eastern Cordillera. Poorer neighborhoods are located to the south and south-east, many of them areas. The middle classes usually inhabit the central, western and north-western sections of the city. Downtown Bogota The urban layout in the center of the city is based on the focal point of a square or plaza, typical of Spanish-founded settlements, but the layout gradually becomes more modern in outlying neighborhoods. Important landmarks and tourist stops in Bogota include the botanical garden José Celestino Mutis, La Quinta de Bolivar, the national observatory, the planetarium, Maloka, the Colpatria observation point, the observation point of La Calera, the monument of the American flags, and La Candelaria (the historical district of the city). The city has numerous green parks and amusement parks like Salitre Magico or Mundo Aventura.