One side of the altar, which was probably surmounted by a statue, shows a depiction of the mythological episode of the Shewolf nursing The Twins.
Present at the scene are the god Tiber and, in the background, a personification of the Palatine Hill with two shepherds, one bearded and one younger, identified as Faustulus and Faustinus. On the opposite side there is a representation of the Marriage of Mars and Venus in the presence of Eros and Silvanus, protector of the college of shepherds of Ostia, to whom the words engraved on the altar are dedicated.
In the rich decoration of the altar, the theme of the divine origin of the Roman people is linked to the union of Mars and Venus, mythological progenitors and a symbol of fidelity and harmony.