A fine Tuscan city - with tower attached

A large, disagreeable city," the Shelleys called Pisa when they first arrived in 1818 - not realising that this was where they would spend most of their Italian exile together. The first reaction of modern tourists is often similar: they tend to treat Pisa as a stopping-place on the way to Florence or Siena, staying overnight at the most. The modern airport, 10 minutes away by rail or bus, is better served from Britain than the one at Florence - particularly since it now receives low-cost airlines - which may be part of the reason the city is seen chiefly as a gateway to other parts of Tuscany.

A large, disagreeable city," the Shelleys called Pisa when they first arrived in 1818 - not realising that this was where they would spend most of their Italian exile together. The first reaction of modern tourists is often similar: they tend to treat Pisa as a stopping-place on the way to Florence or Siena, staying overnight at the most. The modern airport, 10 minutes away by rail or bus, is better served from Britain than the one at Florence - particularly since it now receives low-cost airlines - which may be part of the reason the city is seen chiefly as a gateway to other parts of Tuscany.

Not that anyone denies the interest of the famous Leaning Tower, or the buildings associated with it on the so-called Campo dei Miracoli - the Cathedral, the Baptistery and the Campo Santo, a group of structures that Dickens described as "the most beautiful and most remarkable of its kind in all the world".

But modern travellers who gasp at these wonders have missed the real charm of Pisa, which has ingeniously managed to pack all these major marbles into a small corner at the north-east of the city, fenced in by a row of booths selling souvenirs to tourists: T-shirts, paperweights and, of course, models of the tower. Here, neatly packaged, is what everyone comes to see, and they can see it almost without troubling the life of this walled and quite small Tuscan town.

Five minutes' walk away from the Campo Santo is the Orto Botanico, behind a gate in the Via Luca Ghini. Moved here at the end of the 16th century, this claims to be the first botanical garden in Western Europe, a collection of trees and shrubs with bamboo groves, a lake with turtles and an encyclopaedic garden in which the plants are arranged neatly in rectangular beds to illustrate family resemblances between them.

But what is that you can see over the north wall? The leaning tower again, but a different leaning tower, unfamiliar, surrounded by silence and framed in green branches.

No one here tries to sell you a model of it in a snowstorm, no one takes a photograph as if holding it up. The garden is almost empty, with only a couple of old men talking in one of the alleyways and a few students from the university sitting under the trees, reading. This is the other Pisa; not hard to find, but easily ignored by those who flock to the Campo dei Miracoli.

Nor are the pleasures of this forgotten Pisa just the tranquil ones of the botanical garden. The centre of the town is busy and bustling. Largely pedestrianised, Pisa is a city of bicycles, which weave in and out of the walkers on their evening passeggiata with remarkable but unnerving skill. Heaps of them are parked together at the sides of streets, rows of rusty spokes and pedals interlocked so that it is hard to tell one machine from another.

The Pisan population, in university term time, is young, busy and cycle-mounted. They are supplied with good bookshops, such as Feltrinelli's in the Corso Italia, which has a large reading room at the back, and there are restaurants where they can eat well, cheaply and simply.

But there is little point in trying to do anything fancy with Tuscan cooking; this is peasant fare: bean soups, bread, oil and spaghetti with accompaniments di terra or di mare, according to whether the farm or a fishing boat supplied the ingredients.

Days can be spent walking along the Lungarno and exploring the city's old churches (such as Santa Maria della Spina which has wandered across the road on to the river embankment). The town was badly damaged by bombing during the war, but there are still plenty of old buildings and narrow streets left to wander. Among them is the splendid Piazza dei Cavalieri, with its sgraffito decoration and its grim story of Count Ugolino who was walled up in one of these buildings in 1288 with his sons and grandsons for a supposed act of treachery.

And by the river you come across the Museo Nazionale. Though it doesn't have the Botticellis you get in the Uffizi in Florence - or the long queues of people waiting to see them - it does have Masaccio, Donatello, Simone Martini and the Pisano family, an altarpiece by Martini, a sculpture of the Virgin by Pisano and a whole room of medieval wooden sculptures. There is a good chance that you will have the place more or less to yourself.

But with all the charms of Pisa, there is no mistaking it is a good place from which to explore Tuscany.

Florence is an hour away by a direct train that costs less than £10 for two adults and a child. Siena takes a little longer: you have to change at Empoli; then you can enjoy the sinister medieval streets and the German tourists peering through binoculars to get a closer look at the withered remains of St Catherine's finger.

You can get to Lucca, Marina di Pisa, Tirrenia, Livorno, La Spezia (near where Shelley drowned), and many other places by rail or road: for example, a bus will take you to the Romanesque church of San Piero a Grado, with its interior wall paintings and unadorned 11th-century exterior.

Earlier this year we spent a day at the carnival in Viareggio, only a few stations away by train. All the Africans who sell lighters, tissues, hats and other goods on the streets of Pisa were heading in the same direction, with bags of confetti. The carnival is a noisy, boisterous affair, but at the same time rather grave: people throw confetti, dance, spray each other with foam, but rarely seem to smile or laugh. The confetti lingers in corners of one's clothing for days, even weeks, after.

I talked to one Senegalese with a handful of disposable lighters, and he told me, staring somewhere beyond my shoulder, that life is only a moment, that we soon vanish, that nothing lasts.

The carnival procession was preparing to march along the seafront: the floats are noisy, grotesque and taller than the surrounding houses. The merriment is melancholy and even savage: after all carnevale - "farewell to meat" - is about entering a period of austerity, self-denial and meditation.

It is still hard to find a good guidebook to Pisa. You have to do most of the work for yourself, walking the streets, looking into churches and public buildings, finding the best shops for ice-creams or the best wood-fired pizza ovens or the best spaghetteria.

You may meet the Nepalese man who owns the jewellers in the market - he has lived here for almost a decade with his family and goes home every year to get silver and precious stones for his shop. He intends to return to Nepal for good and bring his children up with "true values", instead of the debased ones of the West.

Or, late at night in the station bar (a fairly depressing place at the best of times), you may run across Nardue, a Moroccan who told us his life story, how his mother and father had abandoned him, how he had made his own way in life, before waving a handful of notes to show us how well he was doing.

The secret of Pisa's charm is that it is not a museum but the living essence of everything Tuscan; the Shelleys eventually came to consider it as home. The local authority has plans to develop the town's tourist potential. Let's hope they don't try too hard.