Yet perhaps they had good cause to be circumspect about the cuisine. Local taste in Mantua is regarded, even by other Italians, as more than mildly eccentric. Their principal peculiarity is stracotto di asino, or braised donkey, but they also concoct strange brews of broth - with generous helpings of Lambrusco added for good measure.
Such culinary habits, so the guide books informed us, became standard fare during the three centuries when the Gonzaga family ruled Mantua and the outlying area. From the early years of the 14th century until 1630 (when Hapsburg troops sacked the city), the dog-loving, horse-mad Gonzaga dukes held court with flourish - and, of course, their influence extended not just to hunting, food and finances, but also fine art. Dietary considerations aside, you come to Mantua to see the remaining legacy of the Gonzagas, feasting on the visual riches of Leon Battista Alberti, Andrea Mantegna and Giulio Romano.
Mantua might not come top of the tourist list in northern Italy. Most of its movable treasures have long since been siphoned off by Florence's Uffizi and other galleries. And set in a flat, marshy landscape it can hardly boast attractive surroundings. Yet the ancient heart of the city contains lovely streets and handsome, intriguing buildings such as the medieval church of the Rotonda di San Lorenzo built in a perfect circle, the elegant clock tower of the Palazzo della Ragione. It is also a relatively peaceful place: unless you arrive at the very height of summer you won't get mown down by hordes of hasty sightseers. For the most part those who visit Mantua come with the quiet intent of admiring the art and architecture of three great men of the Renaissance.
Musician, playwright, mathematician, athlete, architect (the list goes on), Leon Battista Alberti came unnervingly close to being the ideal Renaissance man. He designed his big, bold church of San Andrea in the city's old centre in 1472 as a sort of hybrid of Etruscan and Roman temples (complete with triumphal arch on the facade). The resulting airy spaciousness seems radical - particularly if you take as a point of comparison all those bosses and buttresses of St George's Chapel in Windsor which was started on almost exactly the same date. You can't help gasping as you walk into the church: the wall decorations seem the ultimate in trompe l'oeil. Another Renaissance master, Andrea Mantegna, devised the interior (much of it completed after his death), with every available surface looking, at first glance, as if it is coated in carved marble. But you soon realise with an increasing sense of awe that most of this is painted illusion.
You find more of Mantegna at the ducal palace. The visitors' modest entrance belies the grandeur and labyrinthine quantity of rooms here: even if your Italian is not up to scratch, it's a good idea to join a guided tour if only to avoid getting lost. Your trail will take you through stark halls displaying rediscovered frescoes by Antonio Pisanello, past huge Flemish tapestries of Raphael's cartoons, and to room after room sumptuously designed and decorated by that other great Renaissance (and Mannerist) exponent, Giulio Romano. Highlight of a visit here, however, is a sort of side-swipe into the 14th-century Castello di San Giorgio. Although there's not an enormous amount to see, you'll want to spend as long as you can in the small Camera degli Sposi, with its wonderful frescoes by Mantegna, painted for Ludovico II Gonzaga and his wife Barbara of Brandenburg. Your visiting time is limited, since even your breath has a corrosive effect on the fragile painting. However, we managed to smile sweetly at the guards and gain an extra few minutes to absorb the Gonzaga family scenes (great dogs, fantastic backgrounds) and the cherubs and peacock perched precariously around the painted cupola, as well as to pinpoint the tiny self-portrait of Mantegna himself, shrouded among the marble-like decorative embellishment.
The most revolutionary work of Mantua's third great Renaissance hero lies at the other end of town, beyond more modern developments. Giulio Romano's Palazzo del Te was commissioned in 1527 by Federico II Gonzaga who wanted a home for his mistress. Here Romano transformed a set of old stables into an elegant palace and in so doing set in train the new Mannerist movement - defying Renaissance ideals by wilfully misusing classical motifs (huge keystones in the facades, and the unheard of use of Tuscan columns). Inside, there's a wealth of wall decorations, from pretty stucco work to riotous frescoes. The thundering titans of the Sala dei Giganti may seem a bit over the top, but the witty frescoes of the Salone dei Cavalli (Hall of Horses) are bound to appeal. Here Federico's many thoroughbreds stand proudly on ledges and look out at you from above the doorways.
Such a show of grandeur is a far cry from the mood of Mantua today, which is well-to-do in a low-key way. Back in the old part of town there's a cheerful mix of sleek style and stoic conservatism - as you wander through Piazza Mantegna you can't help being struck by the fact that a Giorgio Armani outlet sits expensively opposite a little haberdashery store, its shop-front festooned with buttons. The most attractive windows, though, are those of the cake shops - and there are many. The Mantovans are clearly keen on their cakes, and among the delicious displays of praline tarts, chocolate and orange torta and amaretto confections there's a reminder of their curious culinary taste: torta di tagliatelle is composed of sugar-coated pasta twirled into a bird's nest arrangement above a crumbly shortbread base. What a calorie count - quite enough to worry even the most wayward weight watcher.
How to get to Mantua Harriet O'Brien paid pounds 215 for a return Gatwick- Florence flight on Meridiana (0171-839 2222). She rented a car from Hertz (0990 996699) for pounds 200 per week. If your sole destination is Mantua, then the most accessible airport is Verona, with Milan and Bologna as good alternatives.
How to get to Rome The best scheduled fare at present is on Debonair (0500 146200) from Luton to Rome's Ciampino airport. The company's lowest fare is pounds 149.70 return, including tax. Sky Shuttle (0181-748 1333) and other discount agents offer cut-price charter and scheduled flights to Rome and many other Italian cities.
More information The Italian State Tourist Office, 1 Princes St, London W1R 8AY (0171-408 1254).