To be found in Castello, in the sotoportego (underpass) de la Corte Nova, is piece of red Verona marble set into the paving blocks. The story goes that during the plague of 1630, many people who lived in the Corte Nova were saved from death when they gathered to pray within the sotoportego to the Virgin Mary and the Saints Roch, Sebastian and Lawrence.
The piece of red marble was placed in the sotoportego to serve as a memorial to this miracle. Now, some say it is bad luck to step on it, while others say the opposite. What is one to do?
I was just reading more about this in Secret Venice, by Jonglez and Zoffoli, and found that residents prayed here to the Madonna during enemy shelling during World War I, and were spared from injury. Each year, on 1 May and 21 November, Our Lady of the Rosary is honored in this sotoportego.