San Marco is one of the districts of Venice. It is bordered to the north by the Grand Canal, to the south, where the Piazza overlooks the Venetian Lagoon, to the west by the Rio di Palazzo and to the east by the Rio di San Giuliano.

The sestiere di San Marco is connected to the sestiere di San Polo via the Rialto Bridge and to the sestiere di Dorsoduro via the Accademia Bridge.

The island of San Giorgio Maggiore also belongs to the sestiere di San Marco, where the basilica of the same name and the great convent where the Giorgio Cini foundation is located today are located.

It was originally called Rivoalto, hence the name Rialto, and was the original nucleus of the city.

The heart of the district is Piazza San Marco, which for just over a millennium was the political and judicial center of the Republic of Venice. The square is dominated by the Doge's Palace, seat of Venetian political power since the 9th century, and the Basilica di San Marco. The Marciana area is home to other important museums: the Correr Museum and the national archaeological museum, to which are added the historical rooms of the Marciana library. Other places of interest are the Gran Teatro La Fenice, the church of San Moise, the church of Santo Stefano and the Palazzo Grassi, converted into a prestigious art exhibition venue.

Attractions in San Marco area, Venice