Etruscan Terracotta Antefix, Head of Silenus, from sanctuary of Portonaccio, 6th-5th century BC. In Greek mythology, Silenus was a companion and tutor to the wine god Dionysus. The sanctuary of Minerva at Portonaccio is an archaeological site on the western side of the plateau on which the ancient Etruscan city of Veii, north of Rome, Italy, was located. At Villa Giulia, Rome