Venice, the self-styled La Serenissima, is situated in a crescent-shaped lagoon in north-eastern Italy, separated from the Adriatic Sea by a series of narrow islands and peninsulas. The historic centre of the city known by Ruskin is built on a series of small islands and mud banks measuring about 1 mile by 2 miles. The built fabric of Venice comprises numerous self-contained island communities which are joined to their neighbours by footbridges which cross the many canals that form the major transport routes of the city. These self-contained communities are centred around churches and squares which historically provided the focus for their commercial existence. See also Ruskin and Venice.