Since ancient times man used to protect certain areas for religious or historical reasons, but from the nineteenth century the main objective of protecting natural areas became the preservation of scenic beauty and ecological purposes. It was thus consolidated the concept of Natural Protected Areas, which are called today, in Brazil, of Conservation Units. Although most extent of these areas are situated outside cities environments, there are also Urban Protected Areas, of enormous importance. Over the decades, however, many parks created in Natural Protected Areas became just paper parks, not reaching their purposes.