The city of Bragança is split by the river Fervença: The left bank is flat and urban (where the city proper is) and the right bank is sloping (the river mingles with vegetation). In the mid-twentieth century all around the river was completely degraded and polluted, urban waste was dumped uncontrollably. In 2000, through the "Polis Program", considerable intervention was planned to recover the environment and integrate it into the city as a recreational green area. Thus a sewage treatment plant was constructed and a so called "green corridor" created. This is a very nice landscaped promenade running along the course of the city's river.