By the 1950s, this older section had become run down and known as the Second District. As a large part of its main commercial houses had transferred to the city's First District, on the left bank of the river, following the construction there of the main public offices and residences of the most important families. Today, Rio Branco is seeking to find ways to reinvent itself, through relations with neighboring countries, developing heritage and eco-tourism, building on the local fish farming industry, and so on. Geography Rio Branco is located at 9° 58' 29" south and 67° 48' 36" west, at an altitude of above sea level. The city has developed on both sides of the Acre River, with areas known as the First (left bank) and Second Districts. The river is crossed by six bridges, the newest bridge being the Joaquim Macedo Catwalk. Rio Branco is located in the mesoregion of Vale do Jurua and the microregion of Rio Branco. It is bordered on the north by the municipalities of Bujari and Porto Acre; to the south by the municipalities of Xapuri, Capixaba, and Plácido de Castro; to the east by the municipality of Senador Guiomard; and to the west by the municipality of Sena Madureira. Vegetation The Amazon rainforest represents over half of the planet's remaining rainforests and comprises the largest and most species-rich tract of tropical rainforest in the world. Wet tropical forests are the most species-rich biome, and tropical forests in the Americas are consistently more species rich than the wet forests in Africa and Asia. As the largest tract of tropical rain forest in the world, the Amazonian rainforests have unparalleled biodiversity. More than one-third of all species in the world live in the Amazon rainforest. The municipality contains part of the Chico Mendes Extractive Reserve, a sustainable use environmental unit created in 1990. Climate The city of Rio Branco has the lowest average annual temperature among Legal Amazonian and Northeastern capitals. The city has a tropical monsoon climate, with temperatures between during the hottest days of the year. The lowest temperatures occur at night, with frequent records of at dawn. The period from December to March is the hottest time of year, with highs of or more. Usually between May and August, the region experiences a cooler weather, registering lower temperatures (around ) compared to regional standards. In July 2010 the city experienced record