Mestre is situated in the Venetian Plain on the margin of the Lagoon of Venice (3 m a.s.l.) and it serves as a gateway to Venice through the Ponte della Libertà (Liberty Bridge). Overlooking the lagoon is the San Giuliano Park, inaugurated on May 8, 2004 and with an extension of 74 acres. The main watercourse is the Marzenego, whose original river bed has been over time repeatedly changed and covered. It forks, surrounding the old city, in the north branch called Beccherie branch or San Lorenzo and in the south branch called Muneghe’s or Campana’s branch. The two branches meet at the bridge of via Colombo forming the Osellino, the artificial canal that carries water into the lagoon, flowing in  Tessera. Another important watercourse is the Canal Salso that connects the city and the lagoon. The last stretch in the nearness, which ended at Piazza XXVII Ottobre, was buried in the twentieth century for the realization of the square (at the time called Piazza Barche, place name still widely used) and Via Forte Marghera