The western lagoon (palù de soto) is the largest and with the most islands. It has always been criss-crossed by waterways linking Grado to the port system of Aquileia, as recently highlighted by the finding of a Roman ship of the first century ad. The isola della Schiusa, recently created using excavated material and now wholly urbanised as part of Grado, is part of the western lagoon. The eastern lagoon (palù de sora) is the more recent and shallower of the two. After the reclamation of the area of Fossalon in the first half of the last century, its surface area was effectively halved.