Statue of Castor, Piazza del Campidoglio, Capitoline Hill, Rome
At the summit of the Cordonata, placed on pedestals in a position corresponding with the lionesses at the bottom, are a pair of sculptured groups of Castor and Pollux, each represented with a horse, as they are said to have appeared to the Romans while watering their perspiring steeds at the fountain of Juturna, at the base of the Palatine, whither they brought tidings of the victory over the Tarquins at the Lake Regillus. Both groups were discovered about the year 1580, in the reign of Pius IV, in the square of the Jews' synagogue in the Ghetto, not very far from the spot where the temple erected to Castor and Pollux, in consequence of the above apparition, is supposed to have been situated; and both were removed hither by Gregory XIII about twenty years after the discovery. The statues are of very ordinary execution; and were it not that all are of the same description of Pentelic marble, one would think the men and horses were never intended to stand together—such is the disproportion of the colossal youths to the small size of the horses, which would seem thoroughly incapable of bearing such riders. At any rate, the objects are by 110 means calculated for their prominent position, and were evidently intended by the sculptor to be placed their backs to the wall; and the backs of the men are unfinished accordingly, composed of rough blocks of marble, of which the gaping joints are clumsily held together by iron clamps or rivets.
— Rome. A Tour of Many Days. Sir George Head, 1849