The mouth of the Tagliamento River is a delta. Contrary to what we think, and we are taught in schools, it has only one output channel. The mass of debris, sands and other detrital material transported here meet the force of the winds, in particular those of the sirocco and the wave motion, the material is then distributed along the coasts to its right and left and over the years has formed the two peninsulas of Bibione and Lignano Sabbiadoro.
Before the construction of Lignano and Bibione (in the 1950s), which involved reclamation of the area, the landscape was very different. In fact there were marshy areas and, towards the sea, large sand dunes as documented by ancient maps such as the one presented here, dated 1740.
Today some parts of the original dunes can still be seen, in part, in the area of the park at the mouth of the Tagliamento, while elsewhere they have been destroyed.