The city floor is one of the three main elements of urban composition. Apart from the walls, which in a city are created by the façades of buildings, and the ceiling – here usually the sky – the city floor co-creates the urban interior. The floor in the public spaces deserves a special attention because of its accessibility and the public nature. The last thirty years in our country was a period of intense modernization of city floors in existing urban public spaces. Th is process is still continued. The inspiration for this kind of realizations can be, inter alia, Italian historical piazzas whose floors were formed with special care. Th is article discusses and analyses the solutions on four squares – Campo in Sienna, Pius II in Pienza, the Campidoglio in Rome and Saint Mark’s in Venice. These four piazzas are well known and have their own place in the history of architecture and urbanism. Nevertheless, they are rarely analysed for their floors and noticed that they owe this special place in history also because of their floors.