Volcan de Agua de Pau dans l'île de Sao Miguel centrale contient une caldeira externe 4 x 7 km formé il y a environ 30 000 à 45 000 ans et une caldeira intérieure 2,5 x 3 km qui a été créée il y a environ 15 000 ans.

The younger caldera is partially filled by the Lagoa do Fogo caldera lake. Several post-caldera lava domes were emplaced on the northern and western flanks of the volcano, but activity in the caldera did not resume until about 5000 years ago. The 3-cu-km Fogo-A plinian pumice-fall deposit, the product of the largest-known Holocene eruption in the Azores, was emplaced at this time. Numerous flank cinder cones mark radial and concentric fissures, some of which have been active during historical time. The latest trachytic explosive eruption took place during 1563. Prominent hot springs are located on the NW flank.