The dominant peak is the Monte Cavo, at 950 m (3,115 ft). It is believed to have erupted regularly until the 1100s BC, discouraging settlement in Latium before then. There are two crater lakes, Lago Albano and Lago Nemi. The rock of the hills is peperino tuff, a combination of ash and small rocks that is useful for construction, and provides a mineral-rich substrate for grape vines.
The ancient Romans called them Albanus Mons. On the summit was the sanctuary of Jupiter Latiaris, in which the consuls celebrated the Feriae Latinae, and several generals celebrated victories here when they were not accorded regular triumphs in Rome. The temple has not survived, but the Via Triumphalis leading up to it may still be seen.
The hills, especially around the shores of the lakes, have been popular since ancient times as a way to escape the heat and crowds of Rome, and there are many villas and country houses to be seen.