Piazza San Marco, or St Mark’s Square as it’s commonly known, is among the world’s most famous public squares, with an equally famous domed Byzantine cathedral sitting along its edge. Work began on Basilica di San Marco, named after the saint who is apparently buried here, in the 9th century and it was the private chapel of the Venetian doges, or dukes, who resided in the adjacent Doges’ Palace. Today, more than 43,000 square feet (around 4,000sq m) of golden mosaics adorn the cathedral’s internal walls, many from the 13th century.