The Vulsini volcanic complex in central Italy covers about 2200 sq km at the northern end of the Roman magmatic province.
Following lava extrusion and explosive eruptions that constructed the main Vulsini complex, the 16-km-wide, lake-filled Bolsena caldera on the east and the 8 x 11 km Latera caldera on the west were formed during major Pleistocene explosive eruptions at about 0.3 and 0.16 million years ago, respectively. Five major plinian fall deposits were erupted from vents at or near Latera caldera during the late Pleistocene. The latest major eruption formed unwelded pumice flows and welded airfall tuffs of the Pitigliano Formation, associated with collapse of the Vepe caldera about 166,000 years ago at the NW end of Latera caldera. Post-caldera volcanism produced scoria cones and lava flows from vents within and to the west of Latera caldera and lasted until subrecent times. Youthful-looking remnants of ash cones in Lake Bolsena may have given rise to a legend of a pre-historical fire-god, Volta. An historical report noted that "a flame shot up near Volsini" in 104 BC. Source: Smithsonian GVP