The Garrotxa Volcanic Zone Natural Park covers a holocene volcanic field (also known as the Olot volcanic field). The volcanos (about forty within the park) are no longer active and the last eruption (Croscat) occurred around 11,000 years ago.
The region is still seismically active, though, and a large earthquake in 1428 caused damage to buildings and twenty deaths in Barcelona. More recent earthquakes in 1901 and 1902 caused shaking but little damage.