A sestiere (plural: sestieri) is a subdivision of certain Italian towns and cities. The word is from sesto, or sixth; and is thus used only for towns divided into six districts. The best-known example are the sestieri of Venice, but Ascoli Piceno, Genoa and Rapallo, for example, are also divided into sestieri.
Other Italian towns with fewer than six official districts are frequently divided into analogous quartieri (4, whence the English word "quarter" to mean a neighbourhood) or terzieri (3); some towns merely refer to these neighbourhoods by the non-number-specific rioni. Sestieri, quartieri, terzieri, rioni, and their analogues are usually no longer administrative divisions of these towns, but historical and traditional communities, most often seen in their sharpest relief in the town's annual palio.