Volcanic cones or cinder cones result from eruptions that explode mostly little pieces of scoria and pyroclastics (both resemble cinders, hence the name of this volcano type) that build up about the vent. These can be relatively short-lived eruptions that create a cone-shaped hill maybe 30 to 400 meters high. Most cinder cones explode only once. Cinder cones may form as side vents on better volcanoes, or occur on their own. Parícutin in Mexico and Sunset Crater in Arizona are examples of cinder cones. In New Mexico, Caja del Rio is a volcanic field of over 60 cinder cones.