36. The Guanabara Bay, a Giant Body of Water Surrounded by Mountains in the Rio de Janeiro Metropolitan Area

The Guanabara Bay in Rio de Janeiro is one of the most important Brazilian morphological features, both in terms of its geological and geomorphological evolution as well as considering its historical importance to the development of Brazil. The existing morphological contrast, varying from mountain escarpments, hills, fluvial, and marine coastal plains, beaches, and lagoons, results from a complex evolution that imprinted in the landscape an intriguing diverse morphology which constitutes a highly attractive touristic natural scenario that is well known internationally. Its geological and geomorphological history is related to the Paleogene extensional faults and alkaline magmatism within the Guanabara Graben that was filled by Cenozoic continental and/or fluviomarine sediments. In this landscape, the use of natural resources has constrained human occupation for more than 500 years. It was only in the 2000s that improved environmental consciousness promoted measures toward minimizing environmental degradation processes.