The Piazza del Popolo
Piazza del Popolo was designed by Valadier at the beginning of the IX century; it is considered as one of the best urbanistic buildings in the city. (This piazza was a quiz question for me! )In the middle of the big space the second biggest obelisk in Rome is located, which was brought by the Emperor Augustus, and here erected by Fontana during the time of Sisto V.
On the slopes of the Pincio terrace, from which you can enjoy a wonderful view, stands the church of S. Maria del Popolo, built around the XI century and completely restored during the Renaissance. Inside it you can find many masterpieces by Pinturicchio and Caravaggio. The second aisle from the left side houses the Chigi Chapel designed by Raphael in the Renaissance.
On the square too stand the two Twins Churches of S. Mary in Montesanto and S. Mary of Miracles, that, though very similar externally, present many differences in their interiors.
Another element characterising the big space of the square is Porta del Popolo, which was the most important way for the access to Rome through the consular road Flaminia.