San Marco, located in the very geographical centre of the island, is one of the six sestieri of Venice, lying in the heart of the city. The area also includes the island of S. George Maggiore.

Although the district includes san Marco Square, that was never administered as part of the neighborhood.

It is a small district and it includes many of Venice's most famous sights, including Saint Mark's Basilica, Harry's Bar, the Doge's Palace, San Moisè, the Palazzo Grassi, La Fenice theatre and the churches of San Beneto, Santa Maria del Giglio and San Maurizio.
The area was the location of Venice's government, it is densely built and is now heavily touristed with many hotels, banks and expensive shops.