Solfatara (Italian: Solfatara di Pozzuoli) is a shallow volcanic crater at Pozzuoli, near Naples, part of the Phlegraean Fields (Italian: Campi Flegrei) volcanic area. It is a volcano, which emits jets of steam with sulfurous fumes. The name comes from the Latin, Sulpha terra, "land of sulfur", or "sulfur earth".

From Wikipedia