The municipality occupies the semi-active craters of the Furnas and Povoação volcanoes, circled by forests, mountains and river valleys to the north, west and east, while the Atlantic coast to the south. From 100,000 to 95,000 years ago, the Povoação crater, associated with the volcano, consists of volcanic products that were emitted from this volcano of the same name, that overlay the Volcanic Complex of Nordeste. Corresponding basaltic lava flows and other volcanic ejectants, the top of this formation is covered by materials involved in explosive eruptions from the Furnas volcano.