Concepción volcano is a steep symmetrical stratovolcano with a perfect shape and one of the most active volcanoes of Nicaragua. During the past 100 years, it has been in a near-constant state of small to medium ash explosions at irregular intervals.
Together with its neighbor Madera volcano Concepción forms the NW half of the dumbbell-shaped island of Ometepe in Lake Nicaragua. Both volcanoes are connected by a narrow isthmus.
Frequent explosive eruptions during the past decades have increased the height of its summit significantly (more than 100 m) and outdated the existing topographic maps. Because of the frequent ash eruptions, the upper half of the summit cone lacks vegetation.
The basaltic-to-dacitic Concepción volcano contains a steep-walled 250 m summit crater with a higher western rim. Flank vents are aligned on N-S-trending fractures and contain chains of spatter cones, cinder cones, lava domes, and maars on the NW, NE, SE, and southern sides. Some of these vents are found down to Lake Nicaragua.