Solfatara is a shallow volcanic crater at Pozzuoli, near Naples, and is part of the Campi Flegrei volcanic area. The name comes from the Latin, Sulpha terra, "land of sulphur". It was formed around 4000 years ago and last erupted in 1198 with what was probably a phreatic eruption - an explosive steam-driven eruption caused when groundwater interacted with magma. The crater floor is a popular tourist attraction, as it has many fumaroles and mud pools. The area is well known for its bradyseism.