Venice, known as the "Queen of the Adriatic," is a city apart. It is considered one of the most beautiful cities in the world. It rests on an archipelago of 120 islets formed by 177 canals on the lagoon between the mouth of the Po and Piave rivers, at the northern end of the Adriatic Sea. The buildings are supported by countless millions of larch poles driven into the sediment. The islands on which the city is built are connected by about 400 bridges. Today, about 85,000 Venetians live in this beautiful, preserved city but during its 16th century heyday its population numbered almost 200,000. Venice's main modern industry is tourism but it still retains the atmosphere of its historic past.