 The hill was known as "Mons Vaticanus" or "Clivus Cinnae" (from the name of the Consul Lucius Cornelius Cinna) during the ancient Roman period.The current name, according to some theories, comes from Mario Mellini, a cardinal who owned a villa (since 1935 the seat of the Museo Astronomico e Copernicano of Rome) and several hamlets around the hill in the 15th Century.A second hypothesis derives the name from the word "mare" (Italian for "sea"), referring to the fossil shells found there or to the fact that from some heights is it possible to see the sea.