Venice (Italian: Venezia, Venetian: Venezsia, Latin: Venetia) is a city in northern Italy, the capital of region Veneto, and has a population of 271,251 (census estimate January 1, 2004). Together with Padua, the city is included in the Padua-Venice Metropolitan Area (population 1,600,000). Venice's nicknames include "Queen of the Adriatic", "City of Water", "City of Bridges", and "The City of Light". The city stretches across 117 small islands in the marshy Venetian Lagoon along the Adriatic Sea in northeast Italy. The saltwater lagoon stretches along the shoreline between the mouths of the Po (south) and the Piave (north) Rivers. The population estimate of 272,000 inhabitants includes the population of the whole Comune of Venezia; around 62,000 in the historic city of Venice (Centro storico); 176,000 in Terraferma (literally firm land, the areas outside the lagoon), mostly in the large frazione of Mestre and Marghera; and 31,000 live on other islands in the lagoon. The Venetian Republic was a major maritime power and a staging area for the Fourth Crusade, as well as a very important center of commerce (especially silk, grain and spice trade) and art in the Renaissance and up to the end of the 17th century.