I visited Piazza San Pietro in Vatican City on a late Tuesday afternoon in May. The area near St. Peter’s Basilica was cleared of people as they prepared seating for the Wednesday morning mass. Rain had cleared many of the visitors from the area, providing a rare moment where the square seemed free of people.
Piazza San Pietro is an immense space, and as with all Vatican architecture, leverages techniques to give the maximum aesthetic impression to visitors. The piazza leverages a false perspective as it opens to St. Peter’s Basilica, giving the illusion of a building even bigger than it is.
While I find the cathedrals of Sagrada Familia and Chartres more aesthetically pleasing, nothing compares to the sheer scale of St. Peter’s Basilica.