The nave of the basilica is so long that it obscures the view of the dome; it isn't possible to see the full height of Michelangelo's dome from the square. To see the entire dome, you have to back out of the Square down Via della Conciliazione, which was only possible once Mussolini opened up the boulevard in the 1930s. Steves says of this: "Although I don’t make a habit of thanking fascist dictators, in this case I’ll make an exception: “Grazie, Benito.”"