You are at the end of the elegant Via Toledo in the magnificent 25,000 square meter piazza with its large semi-circular arcade: this is an unexpected space in the heart of a city with a notoriously congested urban layout. Created at the end of the 18th century as part of a Neoclassical urban project, it is also the main venue for large popular events in the city.
To get a general overview of the square, I suggest going to its center, more or less even with the two twin palaces: Palazzo Salerno facing the sea, and Palazzo della Prefettura facing inland.
Turning your back to the Royal Palace, right in front of you is the Neoclassical Basilica of San Francesco di Paola, with eight columns on its façade and a central dome flanked by two smaller domes. In the space surrounded by a semicircular colonnade, you can see the horseback statues of King Charles III on the right and his son Ferdinand I on the left: the first one is by the great 18th-century sculptor Antonio Canova and the second was designed by the same and completed by his pupil.
And the name "Piazza del Plebiscito"? It refers to the plebiscite, a sort of popular referendum of 1860 in which the Kingdom of the Two Sicilies was annexed to the Kingdom of Sardinia, which would then become the Kingdom of Italy.
The square's current shape of a semicircle attached to a rectangle is decidedly quite scenic, and is the result of several restructuring projects that have taken place over the centuries since the 1600s.
Until the end of the 16th century, this area was simply a dirt clearing that was used for popular festivals. Leveled to build the Royal Palace, it became the new vital center of the city and a meeting place for the nobility of the time, who until then had been pushed beyond the boundaries of the historic center.
FUN FACT: there is a long-standing challenge between Neapolitans and tourists in Piazza del Plebiscito. You have to cross the square blindfolded, starting from the door of the Royal Palace and passing between the two horses. So far nobody has ever managed!