The term canal is used in the historic center to indicate the waterways which, due to their width, length and density of sustained traffic, constitute the real backbones of the navigation system inside the city. They are: the Grand Canal, which crosses the whole heart of the city from west to east separating it in two and ends in the San Marco Basin; the Cannaregio Canal, which joins the initial part of the Grand Canal with the northern part of the lagoon in the direction of Mestre; the Giudecca Canal, which connects the western part of the city to the south directly with the San Marco Basin; the Scomenzera Canal, which directly joins the Giudecca Canal with the initial part of the Grand Canal in Santa Chiara, passing between the Stazione Marittima and the Santa Marta area. Outside the urban context, the term canal is used to specifically name the natural navigable lagoon paths that surround the city or that connect it to the mainland or to the inlets, the main canals