Pico Island is the youngest of the archipelago, with about 300 thousand years, having been built over many volcanic eruptions that extend to the present day.
In its landscape stands out as main structures, the Topo shield volcano (south side of the island), which initiated the formation of the island, the stratovolcano of Pico Mountain (with 2351 metres of altitude, in Piquinho zone, and so the highest point of Portugal) and the Cordilheira Central (central cordillera) or Planalto da Achada (plateau) (alignment of about 200 volcanoes: scoria cones, of spatters and eruptive fissures).
In Pico Mountain, at a height of 2250 metres, there is a crater with an average diameter of 550 metres and circular contour, filled by lava flows of Piquinho cone. At this altitude, there are manifestations of secondary volcanism, namely fumaroles.
On land, there were four historical eruptions, which originated the "Mistério da Prainha", between 1562 and 1564 (the historic eruption of longer duration in the Azores), the "Mistério de Santa Luzia" and "Mistério de São João", in 1718, and the "Mistério da Silveira", in 1720.