The Plaza Mayor or Plaza de Armas (as it was known until 1990), is the oldest public place in Lima. In 1535 the conquistador Francisco Pizarro founded on the area of an existing indigenous settlement the city of Lima. He designed the main square in the central part of the future city Lima with all important institutions built around it. On the north side of Plaza Mayor is the Palacio de Gobierno, the presidential residence and in colonial times the location of Francisco Pizarros house - later the Palace of the Viceroys. On the east side, you find flanked by the Archbishop's Palace the Cathedral of Lima. The Palacio Municipal is located on the west side of Plaza Mayor. Depending on their importance and rank wealthy and influential immigrants were allowed to build their mansions on properties near the Plaza Mayor. In colonial Lima, the main square was the economic centre of the city. The arcades in front of the main buildings, the small today called Pasaje Olaya and other adjoining streets were full of all sorts of shops. The plaza housed for a long time Limas big food market. https://www.limaeasy.com/culture-guide/plazas-city-squares/lima-main-square