The town of S.Anna is bordered by Bosco Nordio: a wonderful natural reserve of considerable historical and scientific interest which has remained almost intact since its formation. During the Roman period, the dunes on which it was situated were part of a coastal sandbank which was the prosecution of the one currently delimiting in the east the lagoon of Venice and which continued beyond the river Adige up to the river Po and then to Ravenna. In the Middle Ages, as well as in the Roman period, the sea bordered the current dunes of the coastal sandbank covered with woods. It is a wild wood made of holm oaks, laurels, and pine trees, the same trees growing on the dunes beyond the river Adige.