But when you arrive in the city, don't head straight for the piazza; leave it till after dark. Even in the days before it grew impossibly crowded, the square was always at its best at night. So choose a restaurant that is relatively close—make a little detour if you have to—and take your time over dinner. Then, and not till then—the later the better—stroll to St. Mark's. Let the magic of what Napoleon is said to have called the greatest drawing-room in Europe sweep over you until you are filled with it. Within a few minutes, you will feel that Venice belongs to you, and you will go happily to your bed.

The next morning, you're on your own. Everyone has his or her own idea of how to get the best out of Venice. Some go for the architecture, some long for the pictures; some, I regret to say, think only of shopping, which they can do far better elsewhere—unless they yearn for those nightmare Carnival masks that now disfigure every other Venetian shop window. My own happiest times in the city have been spent walking, with Venice for Pleasure, by Joe Links, in my pocket. Having no cars, Venice is the best walking city in the world. If you don't have Venice for Pleasure, don't worry about a destination; just walk anywhere, heading off in whatever direction takes your fancy. Take a map with you, but don't look at it until you're well and truly lost.

I recently returned from taking two teenage grandchildren to Venice for the first time. We had only four days, so it was important to get the priorities right. Number one, of course, was the basilica. (Nowadays you must go early in the morning, before the tourist crush.) I explained that it was one of the few great religious buildings that wasn't intended primarily for worship—that it was essentially an enormous reliquary, designed and built for one purpose only, to contain the body of Saint Mark when it was stolen from Alexandria by two young Venetians in 828. For this reason, throughout the thousand-year history of the republic, it was never the city's cathedral; if it had been, it would have been subject to the pope, who might at any moment have had the precious relic brought to Rome. Technically, it was the private chapel of the doge, and so remained always under civil power. We looked at the mosaic over the northernmost of the five arches on the west front (the only one, alas, that survives from the thirteenth century) showing the body, in an open coffin, being carried into the basilica—the earliest representation we have of the building, though the four horses are already in place.

While we were still in the piazza, it seemed worth telling them about the revolution that turned fiasco. In June 1310, two noble families, the Querini and the Tiepolo, plotted to overthrow the doge, and agreed that at dawn on the fifteenth they would advance by separate routes to the Doge's Palace. In those days, horses were still common in the city, and the Tiepolo faction galloped in pouring rain down from the Rialto toward the piazza. Then, just before they passed under the clock tower, an old lady named Giustina Rossi tipped a heavy stone mortar out of her first-floor window. It narrowly missed the leader, Bajamonte Tiepolo, but struck his standard-bearer on the head, killing him outright. Seeing their banner lying in the mud, the rest panicked and fled. End of the revolution. Later, when Signora Rossi was asked how the republic could show its gratitude, she requested two things only: that she and her successors in the house have the right to display the flag of Saint Mark from the fateful window on all feast days, and that the rent never be raised. Both requests were granted, together with a further, unsolicited reward. Go some ten yards up the Merceria from the clock tower and raise your eyes to the upper wall on your left: There she is, mortar at the ready.