From my readings, this square is the second oldest in Montreal, after Place Royale next to the port and Pointe-à-Callière Museum.
In 1693, the Place d’Armes (Weapons square) was already meant to be a public area. Once named “Place de la Fabrique” it changed its name to its current name due to military demonstrations that took place in the area.
In the center, there is a monument in memory of Paul de Chomedey, founder of Montreal. This monument presents other important figures of the time: Jeanne Mance, Raphael-Lambert Closse, Charles Lemoyne and an Iroquoian warrior. While it was not in function while we were there, this is a fountain during summer. Street artists, commonly classical musicians, sooth the atmosphere of the square making it a pleasant place to be which is totally in harmony with the surrounding historical buildings around the square.
In front of 500 place d’Armes, at the limit of two corners facing the square, are 2 public art sculptures. The two Snobs are bronze sculptures entitled The English Pug and The French Poodle. More information on the art and artist can be found here: https://artpublicmontreal.ca/en/oeuvre/the-english-pug-and-the-french-poodle/