Sao Paulo’s geography can be divided into three zones: a narrow coastal zone; a sudden mountain chain known as Serra do Mar; and the interior plateau. Serra do Mar visibly divides the coast from the interior lands while the interior plateau stretches from Serra do Mar to the western border of the state.
At the second zone of Serra do Mar, altitudes fluctuate between 800 and 1100 meters; the mountains end rapidly at the coast with an abrupt fall and there is a gentle slope towards the west. The plateau zone has three clear-cut sections within its zone: the area neighboring Serra do Mar has a basement of granite rocks; an extreme valley known as Depressao Interior, which separates two neighbor plateaus and is nearly 200 m deep; Planalto Ocidental, a plateau which envelops nearly half of the entire State.