St Mark's Square or Piazza San Marco, is the principal public square of Venice, Italy, where it is generally known just as "the Piazza". All other urban spaces in the city are called "campi". The Piazzetta is an extension of the Piazza towards the lagoon in its south east corner. The two spaces together form the social, religious and political centre of Venice and are commonly both considered together. This article relates to both of them.