First of all, the square is famous for the Quirinal obelisk with a fountain. As usual, the holy fathers did not let antiquities go to waste in the economy. An obelisk from the mausoleum of Augustus, statues of the divine Dioscuri from the baths of Constantine (which in turn (the statues) were Roman copies from the originals of Phidias and Praxiteles), and an antique pool from the Roman Forum was used for the fountain. Inspection is included in the sightseeing tour of Rome. But if you do, then sure.→