Volcanic neck

Volcanic neck   is  the solidified remains of volcanoes’ conduit and plumbing systems that remain after the rest of a volcano has been eroded away

Besides the volcanic neck, differential erosion may also reveal resistant dykes which have solidified in fissures of the original cone. Examples include; Mawenzi peak on Mt. Kilimanjaro, Batian and Nelion peaks on Mt Kenya, etc.