The square is continuous on its north side with the Avenida dos Aliados, an important avenue of the city.

The square was initially limited by the medieval walls of the city and by urban palaces, all of which are now lost.

The municipality moved to a building on the north side of the square after 1819, and towards the end of the century facilities like the D. Luís Bridge (1887) and São Bento Train Station (1896) were opened nearby.

[1] In 1866 a monument dedicated to King Peter IV, a monarch closely linked to Porto, was inaugurated in the middle of the square.

The monument, by French sculptor Anatole Calmels, consists of a statue of Peter IV riding a horse and holding the Constitution that he had fought to protect during the Liberal Wars.