<prompt> Translate the following text to EnglishPiazza della Certina ni moja ya maeneo muhimu zaidi ya mji wa Italia, na pia ina majengo ya kifahari ya kifalme, pia ina piazza del Duomo, ambayo inajumuisha kanisa na ukumbi wa mji kama kituo cha nguvu za kiraia na kidini, na pia pia pia  <response>: The most important are clustered around three adjoining the triangular Piazza della Ceterna named after the citys 13th-century travertine well, surrounded by elegant palaces; the Piazza del Duomo, grouping church and town hall as the center of civic and religious power; and the Piazza delle Erbe ?market place with twin Salvucci towers. 