When visiting any city, my advice is always to look up as you walk around. Many of the most interesting details of buildings tend to be above your head, street level usually being reserved for modern shops and tarmac pavements. When visiting Venice’s Piazza San Marco, however, my advice would be the opposite since there are many interesting details that most people miss, right under your feet.
Piazza San Marco has, since 1723, been covered in a pavement of trachyte, a volcanic stone mined from the Euganean Hills near Padua, with a geometric design worked out in white marble. The project was designed and executed by Venetian architect Andrea Tirali (1657–1737). A Canaletto painting from 1723, which can be contrasted with later paintings, shows the piazza covered with beaten earth, ready for the laying of the paving stones, known to the Venetians as masegni.
The pavement itself can be viewed from the Campanile di San Marco and also from the windows of the Museo Correr at the far end of the piazza (see the photo at the top of this page). However, walking around the piazza, you can find several different items of interest at pavement level.
In the far left hand corner of the square, facing away from the basilica, you can find a some large concentric circles carved into the paving stones. These, we are told from the inscription in the centre, mark the position of a well which once stood in the square, but was filled in in the 16th century.
Moving into the centre of the square are two inscriptions commemorating the 1625 grant of the right for two of the Venetian guilds to erect market stalls in the piazza. On one side the pitch is reserved for the guild of Calegheri (shoemakers) and on the other side the guild of Zavatteri (clog makers). It seems that the piazza was the place to buy footwear in the 17th century.
Some people have theorised that the marble design itself denotes the position of market stalls. However, there is no evidence for this. Only two guilds are named in inscriptions whereas we know that other guilds, such as the Arte dei Strazzaruoli (second-hand clothes dealers) sold their wares in the piazza and of course wine was sold in the shadow of the campanile, which is how the Venetian word ombra meaning ‘shade’ came also to mean ‘a glass of wine’. Paintings by Canaletto clearly show that the market stalls in the square do not follow the markings. They form, therefore, just a design.
One final thing that you can see on the floor of the piazza, is located underneath the Sotoportego de San Geminian, at the far end of the square, under the Correr Museum. This commemorates the church of San Geminian (San Gimignano) which once stood at this end of the square facing the basilica. Designed by the great architect Sansovino, who contributed many other buildings to the piazza, it was demolished in 1807 to make way for the so-called Napoleonic Wing, today home to the Correr Museum.