What did the Med used to be like before the developers and the tourist trade moved in? Can anyone remember? The answer may in the Gargano Peninsula.

In the ninth and 10th centuries, when the English travelled to the Continent it was more often than not to make a pilgrimage to Monte Sant'Angelo in southern Italy.

In the ninth and 10th centuries, when the English travelled to the Continent it was more often than not to make a pilgrimage to Monte Sant'Angelo in southern Italy. It was here that the Archangel Michael in person had founded a Christian church to replace a pagan oracle and left part of his cloak as a memento. So excited were the Normans by the tales of wealth and plenty brought back by pilgrims to this Byzantine outpost on the Gargano Peninsula, that they sent armies not just to see, but to seize.

For almost 1,000 years, we tended to steer clear, while the Italians capitalised on the wonderful coast that wraps round the south of the country. The Gargano Peninsula, a piece of Albania that stayed behind when the Balkans separated from Italy, is one of the most beautiful parts of the whole Italian coast. Sticking out as a spur above the country's Apulian heel, its 200-mile coastline is marked by startlingly white cliffs and a multitude of little coves where boats and bathers can rest. And, thanks to a harvest of cheap flights to the south of Italy that are yours for the picking, you can discover a region in the gentlest, quietest of autumnal decline.

In a sense, history has turned southern Italy on its head. For 10 centuries after the decline of the Roman Empire, conquest and political instability through the rules of Byzantines, Normans, French and Spanish left the southern Italian coasts vulnerable to piracy and pillage. Vieste still preserves the stone on which 5,000 of its inhabitants were beheaded by the Turks in 1554. As late as the 18th century, the farmhouses on the sea plain were being fortified for fear of attack. Towns kept to the high places and monasteries to the plateaux above. Now, though, the coast is the magnet for humanity.

In the high season, the Italians flock from Rome, and from points north, to the camp sites and small hotels in the woods behind the sandy beaches, to enjoy a family holiday by the sea. So do the Germans, Poles and Czechs, taking their camper vans and tents to the caravan-and- camping villages that lie, half-hidden, among the pines. These are simple, seaside places aimed at families with small children and simple appetites. The best food is to be found in specialist restaurants round the little ports of Péschici and Vieste, along the road that hugs the hillsides and offers such stunning views below.

Yet the high season in these parts is mercifully short – 15 July to the end of August, if you go by hotel prices. By September, it's amazingly quiet. The beach facilities are there. The restaurants are open. But the crowds are not. And the warmth of the Adriatic preserves a semblance of summer well into October.

Yesterday afternoon, I checked fares for anyone wanting to escape to Italy this coming Monday. The closest airport to Gargano is Pescara, and Ryanair's computer offered a flight from Stansted, returning a week later, for under £20. The Essex airport is now the gateway to the south – of Italy.

Like no-frills flying, this corner of Italy is splendidly democratic. It has none of the airs, nor the relentless desire for fashionability, of more celebrated Italian beaches, such as Forte de Marmi, Rimini and Amalfi. Most of the southern Italian coast is for the ordinary family, or couple, not the grand, the noisy or the trendy.

But that is not true of every part, it has to be said. Along the Ionian Sea, the sole of the Italian boot, you can find several hundred miles of uninterrupted beach, once home to some of the richest cities of Magna Graecia and now host to great ribbons of the kind of seaside development that has marred so much of the Mediterranean. There, the mountains have been denuded by logging in the last two centuries and the cities razed by a succession of earthquakes that have helped to impoverish Calabria.

The real glories of the south, however, are the forested mountains and the high plateaux behind them. For generations, the British have ignored the country south of Naples on the grounds that it is barren, bandit-ridden and Mafia-run. The Mafia is indeed there, but outside the big cities it's not in much evidence.

Barren the south is not, other than in the extreme south of Calabria and Apulia. It is a country where the great Emperor Frederick II loved to hunt, a land of forests covering the hinterland and spreading down the mountains to the sea.

On the western side, the mountains are powerful and the scenery is dramatic – most of all along the thin sliver of Basilicatan coast on the Tyrrhenian Sea, which is like the old Côte d'Azur before development – some villas, a few small 10- or 12-room hotels, and some of the best local cooking you'll ever taste. The small beaches are pebbly, wonderful for swimming, but not so good for small children. Further south, in Calabria, the pebbles change to sand, the bays are bigger and the accommodation more modern – although the mountains still keep unrestrained development at bay and provide a magnificent backdrop.

The rest of the Apulian coast is more mixed and less wooded, until you get down to the very heel, around Otranto. The land is flatter, the seashore rockier, and much of it overwhelmed by the horrendous main road that leads to Brindisi and the ferries to Greece.

It is inland that the real cultural treasures lie, in the little towns of Locorotondo and Martina Franca, the city of Matera, with its caves full of paleolithic rock art, in Horace's birthplace at Venosa, and Frederick's castle towns around Melfi, at Cosenza in Calabria amid almost alpine scenery and, of course, Monte Sant'Angelo.

A kind of decoy helps to keep the place serene: Padre Pio's church in nearby San Giovanni Rotondo soaks up the gaudier expressions of modern pilgrimage. Monte Sant'Angelo itself has not changed much over the past millennium. It is still an unspoiled town of Romanesque architecture, ancient alleyways and holy pilgrimage.

Travellers' guide

Getting there: Ryanair (08701 569 569, www.ryanair.com) flies daily from Stansted to Pescara. A fare of £59.48 return was available yesterday for travel out next Saturday, 22 September, returning a week later. Demand on Fridays and Sundays tends to be greater, and therefore fares are likely to be higher.

Go (0870 6076543, www.go-fly.com) flies daily from Stansted to Naples. On the same dates, a return flight was priced yesterday at £222.50, but lower fares are available midweek or by booking further in advance.

More information: Italian State Tourist Board, 1 Princes Street, London W1R 8AY (020-7408 1254; www.enit.it).