This is the first of the great Fontana fountains, and if Domenico Fontana got his inspiration for it from the beautiful public fountain made by Amannati for Julius III on the Via Flaminia, with which he was familiar before the Casino was placed above it, his fountain in its turn became the prototype for the great fountains erected in the next century by his brother for Pope PaulV.
This Fountain of the Moses is a great portal consisting of three arches equal in size, from the base of which the water issues in double cascades. The water falls into three large basins guarded by couchant lions, and each lion spouts an additional stream of water. In the centre archway stands a colossal figure of Moses in the act of striking the rock, and the niches on either side of him are filled by high reliefs of scenes from the Old Testament relative to the importance and significance of water. The relief to the right represents Gideon testing his soldiers and is the work of Flaminio Vacca, and in the left Giovanni Battista della Porta has carved the scene in the desert after Moses has brought the water from the rock. Four beautiful marble columns with Ionic capitals stand one on either side of these arches, and in the small triangular spaces between the capitals and the keystones are the emblems of Sixtus V-the star, the three mounts, the pear branch and the lion. These arches and columns support a massive entablature of which the inscription, in the noble Six-tine caligraphy, forms the most important feature, and is, in fact, the most impressive part of the entire structure. Above the inscription rises the florid pediment, flanked by two obelisks (an idea distinctly borrowed from Amannati’s fountain) and bearing on its apex the three mounts of Sixtus V which carry the huge iron cross. Underneath this and occupying the greater part of the pediment are the armorial bearings of Sixtus V. The huge shield is supported by two angels, a conceit borrowed, perhaps, from Pius IV’s escutcheon over the Porta Pia, and repeated again for Paul V in his fountain on the Janiculum. The armorial sculpture is by Flaminio Vacca. Such is the great Fontana fountain, grandiose rather than magnificent, but still distinctly imposing and adequately filling by its size and importance the honorable position which it occupies among the fountains of Rome.