When settlers first came to Venice in the fifth century it was an uninviting marshland, but the foundations were driven into the dark mud for today’s floating palazzi. The palaces that adorn La Repubblica Serenissima (‘the most serene republic’) were built when Venice ruled a maritime empire that dominated the eastern Mediterranean. But the Republic’s serenity was accompanied by rapaciousness, most famously in the seizure of the four bronze horses from Constantinople that are on display in St Mark’s Basilica (replicas guard the exterior of the church). The Republic fell in the 18th century, and Venice was ruled first by France and then the Habsburgs before finally joining the fledgling Kingdom of Italy in 1866.

While Venice has settled deeper into the mud over the last 100 years there’s no immediate danger of it sinking into the lagoon. However, winter often sees high tides (acqua alta) flooding low-lying areas like St Mark’s Square: sirens wail to warn you to don wellies before the water arrives. For information on Venice’s water situation visit Puntolaguna (campo Santo Stefano 2949, 041 529 3582, www.salve.it), a multimedia centre providing information on activities to safeguard Venice and its lagoon.

If you want to keep your feet dry in style there’s only one option: a gondola. A ride is expensive (about €75 for 50mins) and, well, cheesy, but the gondoliers are generally friendly and, sometimes, operatic (041 528 5075, www.gondolavenezia.it). Only take a gondola from an official stand.

The Grand Canal delineates the six main central neighbourhoods (sestieri). The heart of the city is San Marco, cradled by the great lower bend of the Grand Canal, the Venice of tourist brochure legend. Much of don’t-miss Venice is here, but if you want to get away from the tourist crowds head for the backwaters and boatyards of the quieter districts. To the east is Castello, hard-working, lived-in and traffic- free; to the south, bohemian-chic Dorsoduro is crammed with artistic treasures; to the north, peaceful Cannaregio’s off-the-beaten-track churches are a delight; and, in the eye of the lagoon, Santa Croce and San Polo are full of monuments and ideal places for wandering.

The key sights of San Marco are linked by three main thoroughfares forming a rough triangle: from the piazza San Marco to the Rialto Bridge, from the Rialto to the Accademia Bridge and from there back to the piazza. Sumptuously laid out in Byzantine, Gothic, classical and late Renaissance styles, the piazza is crowned by the Basilica di San Marco (041 522 5205, www.basilicasanmarco.it). The original church was built as a private chapel for the Doge and a shrine for the remains of St Mark in 830. The grand structure we have today dates from its reconstruction in the 11th century. The basilica, with every surface of its interior covered in 4,000 square yards of golden mosaics, is testament to the Venetian links with Byzantium. To see the square from another angle catch the lift to the top of the bell tower (Campanile di San Marco) on the square. From here you have a 360-degree panorama of the city. Alternatively, and ideally, stroll through the square at dawn and be amazed by the serenity.

Also accessible from the square is the Palazzo Ducale or Doge’s Palace (041 271 5911, www.museiciviciveneziani.it), the residence of the Doge (Venice’s elected leader) and the centre of political and legal administration. Inside are grandiose staterooms, adorned with priceless works of art. The Biblioteca Marciana, also in the piazzetta, is the city’s library and seat of learning. Several of its monumental rooms are open to the public; access is through the Museo Correr (041 240 5211, www.museiciviciveneziani.it) at the western end of piazza San Marco. The Correr itself is dedicated to the history of the Venetian Republic. Its second-floor gallery houses a collection of Venetian Renaissance paintings; look out for Carpaccio’s famous portrait Two Venetian Ladies.

Piazza San Marco is linked to the busy Rialto market district by the bustling Mercerie, which passes through church-filled squares, such as campo San Salvador, whose cloisters now house the Telecom Italia Future Centre (www.futurecentre.telecomitalia.it), which provides a journey through advances in information technology. The route from the Rialto to the Accademia and back to piazza San Marco winds through ornate squares and past the church of Santo Stefano and its leaning tower.

Of the scores of churches, palaces, galleries and architectural treasures outside the San Marco area, a handful stand out. The Gallerie dell’Accademia (campo Carità, Dorsoduro, 041 522 2247, www.gallerieaccademia.org, closed Mon pm), over the Accademia Bridge, is a one-stop gallery for Venetian painting, where masterpieces by Bellini, Carpaccio, Titian, Tintoretto and Veronese hang in splendour. The richest of Venice’s scuole is San Rocco (campo San Rocco, San Polo, 041 523 4864, www.scuolagrandesanrocco.it), whose interior was designed by Tintoretto – his Crucifixion covers an entire wall. More of Tintoretto’s work can be seen at the equally magnificent baroque church of Santa Maria della Salute (campo della Salute). The sacristy of this white pavilion opposite the basilica on the Grand Canal houses Tintoretto’s Marriage at Cana. Nearby, the Palazzo Venier dei Leoni (Dorsoduro, 041 240 5411, www.guggenheim-venice.it) is the former home of Peggy Guggenheim and now holds the Peggy Guggenheim Collection, with works by Picasso, Kandinsky, Miró, Pollock and Max Ernst.

It is inevitable that you will get lost in Venice. Everyone does, even if they have a map. The good news is that getting lost in Venice is a pleasure. Wander down narrow alleys where washing flutters from the windows above, and bridges will lead you further into a labyrinth of archways and canals. However, if your time is limited, then a guided tour might be the best option. These can be booked with the Venice tourist office.

• Tourist information: piazza San Marco, 041 529 8711; Marco Polo Airport, Arrivals hall, 041 541 5887; Santa Lucia train station, 041 529 8727, www.turismovenezia.it.