Thousands of people tread on it every day without seeing it: in the paving of Piazza San Marco, in the half facing the Ala Napoleonica on the Procuratie Nuove side, two concentric circles are incised among the masegni (flagstones) and an inscription runs in a band of pale stone: POZZO INTERRATO NEL SECOLO XVII (well filled in in the 17th century). Beneath those stones the great well of the Piazza still exists.