Between 1561 and 1565 the ancient Porta Nomentana was replaced to Porta Pia by order of Pio IV (hence the name) and was built and designed by Michelangelo. The door, built along the perimeter of the Aurelian Walls, conceals a small curiosities related to the internal decoration of the facade where a plea of patens joined by a stole, and with a central cube of marble makes it perfectly the idea that such ponds barber around with a towel and a piece of soap in the center, and justify the popular belief (not entirely unfounded) of a joke alluding to Michelangelo, who took such a cause of Pio IV Medici, who belonged to the famous Florentine family but it seems to be descending barbers milanese.

Despite this, the pope was still allowed to raise the banner medicean and, given the deep ties between the Medici and Michelangelo, that he wanted “revenge” in this way. Without doubt, the fame of the gate is linked to the famous “breackthrough”, runs a short distance from it, in the city wall from the Italian sharpshooters (soldier of the light infantry of the Italian army) this date September 20, 1870 ended the domination of the papacy and Rome became the capital's Italy. In memory of this event was put on the spot where the hole was opened, a monument in marble and bronze by four pilasters that flank the box for the frames with inscriptions in marble of Frigia who celebrate the return to Italy to Rome and killed during combat.

Before the monument (it was originally located in the middle of the road but for obvious reasons of road was moved almost next to the walls) are the gray granite column on which, on top of a capital decorated with trophies, stands the statue of the “Winged Victory”, placed here to mark the 25th anniversary of the fall of Rome (pictured below shows the place where the breach was opened). The external facade of the Porta Pia has two statues of San Agnese and San Alessandro, placed there by Vespignani in 1851 within specific niches, by order of Pio IX who wanted to remember so the danger was caused by the collapse of the courtroom Covent of San Agnese, where the pope had visited.

During the bombardment of 1870, the two statues suffered a serious injury and, after a long restoration, were put back in place in 1929 (year of the conclusion of the Lateran Pacts). The two sides of the door are connected by low buildings forming a courtyard where you find the Historical Museum of bersagliere: there are preserved memories of the Crimean expedition, campaign for independence, the colonial wars and world wars and, among the many relics of the war 1915-1918, a strip of white cloth of surrender waving by the Austrians on 3 November 1918. Outside the door, amid the public square of Porta Pia, the tall monument to the bersagliere, commissioned by Benito Mussolini in 1932 to the architect Mancini and the sculptor Morbiducci.