Porta del Popolo was the ancient Porta Flaminia of the Aurelian Walls through which, until the end of the 19^th century, all travelers from the north entered Rome. The remodeling of the exterior by Michelangelo and of the interior by Bernini removed every trace of this ancient gateway to Rome.

Nor is there any trace left of the greenery that, until the end of the 15th century, greeted the traveler who came through the gate. The vegetable gardens and parks were swallowed up in progressive phases of urbanization during the following centuries and even more so after the rearrangement of the Porto di Ripetta, the nearby port along the river.
At the end of the 16^th century, Pope Sixtus V began the most important of the Renaissance's urban plans-- from the obelisk he had erected in this piazza, three streets known as the Trident radiated off. This was the first obelisk to be brought to Rome from Egypt and it dates from the 13th century BC. From the time of the Emperor Augustus until its relocation, it had decorated the spine of the Circus Maximus.
After 3 centuries of structural alterations, the area inside Porta del Popolo has remained unchanged since the beginning of the 19th century. The architect Giuseppe Valadier was commissioned to design what was to be the last great achievement of Papal Rome. His work manages to synthesize all the previous work and gives life to a wonderful integration of architecture and natural landscape.