Most famous square of Baroque Rome is located on the former site of the stadium of Domitian. Since the reign of Domitian is a place used exclusively for sports. The remains of the stadium can still be seen under the Church of Sant Agnese in Agone dedicated to the virgin-Martyr, which at this point a miracle happened: instantly regrown thick hair covered the nakedness of 13-year-old Christian woman, exposed to the reproach of the Gentiles. The facade of the Church is executed in 1650-ies architect Borromini.

The main attraction of the square is the fountain of the Four rivers Lorenzo Bernini, made in 1651 and caused great admiration of Pope innocent X, which since then became to provide the artist with protection. The figures of the Fountain are the personifications of the rivers - the Danube, the Ganges, the Nile and the Rio de La Plata. The shapes of the rivers are situated around a rocky reef on which stands the ancient obelisk.

The corner at the square there is the Palazzo Braschi, which houses the Museum of city history. On the corner of the building near the plinth is an antique statue with an ugly face – Pasquino. The statue was found during the laying of the Foundation of the building. For some time the neck of the statue began to appear leaflets with an ironic commentary on various current events.