There are few more romantic cities in the world than Venice, its canals and gondolas only part of the attraction that sees more than 20 million visitors arrive here every year. Famously built on 117 tiny islands, Venice is linked by more than 150 canals and 400 bridges, but the city is actually sinking as water levels rise every year. The city centre is divided into six quarters (sestieri) – Cannaregio, Castello, Dorsoduro, Sam Marco, San Polo and Santa Croce. Venice enjoyed a long history as a powerful trading post before being eclipsed by other cities and nations, but today its art, historical buildings and museums remain a remarkable treasure trove, while a romantic ride on a gondola is a must for any visitor. Here is a guide to Venice.