Heart of the Venetian state, the square has always followed the life and customs of the city. The Doge's Palace was the seat of the government and the supreme magistrates of the republic, as well as a prison. Capital executions took place between the two columns of Marco and Teodoro, while the laws and decrees were announced from the Pietra del Bando, then posted on the Porta della Carta. The Basilica was instead the center of state religious ceremonies thanks to the presence of precious relics and its function as a ducal chapel, in a system in which the Doge was head of the Venetian church and reserved the right to appoint bishops. The power and wealth of the church of San Marco were such that it had its own bishop, distinct from that of the city and from the patriarch, the Primicerio, and that special magistrates the Procurators of San Marco administered its patrimony with life, residing in the Procuratie .

The Cathedral that towers over St. Mark's Square is one of the most admired symbols of Italy's artistic and architectural beauty. It summarizes in itself, with opulent elegance, different styles embellished and harmonized by sumptuous decorations of mosaics, marbles, columns and sculptures.

The National Archaeological Museum of Venice is located on the wing of the Correr Museum and the Marciana Library. Located in Piazza S. Marco, it houses an important collection of ancient sculptures, including some notable Greek originals; there are also ceramics, bronzes, gems and coins, as well as the archaeological collection left in deposit by the Correr Civic Museum, which also includes some Egyptian and Assyrian-Babylonian antiquities. Due to its own formation, it has a strong collecting character, made up as it is by the works collected since the 16th century, by important Venetian families.

Piazza San Marco is surrounded by sumptuous buildings that were the homes of the Procurators of San Marco. With your back to the Basilica of San Marco on the right are the Procuratie Vecchie on the left the Procuratie Nuove.

The Rialto bridge is one of the four bridges, together with the Accademia bridge, the Scalzi bridge and the Constitution bridge, that cross the Grand Canal, in the city of Venice. Of the four, the Rialto bridge is the oldest.