Itria Valley: trulli, vines and white villages.

What is the Itria Valley?

It isn't exactly a valley, but a karst depression in the lower Murgia, in central Apulia, spread across the provinces of Bari, Brindisi and Taranto. It's a countryside of olive trees, vines and dry-stone walls, dotted with trulli: round houses of dry stone, without mortar, with conical roofs. Around them, on the hills, white villages peer out: Martina Franca, Locorotondo, Cisternino and Ceglie Messapica. Alberobello is on the edge and Ostuni, already close to the sea.

What is a trullo?

A limestone building without mortar, with a room under each cone and recesses in the wall for sleeping. First a cistern was dug: the stone came from that excavation and water was scarce. The roof has two layers of limestone slabs, and it's often crowned by a carved pinnacle, the signature of the trullaro master. The symbols painted on the cones, many of them Christian, were added mostly in the late 20th century. The best-known theory about why they were built without mortar is fiscal: that way the count could dismantle them and dodge the taxes of the Spanish viceroy of Naples. Inside they are cool in summer and cold and damp in winter.

Which villages should you see?

Alberobello is the city of the trulli: its trulli have been a World Heritage Site since 1996. Wander among the conical roofs of the Rione Monti, look for the Trullo Sovrano and the church of St Anthony of Padua, and notice the pinnacles: each one is different. Go early, before the groups arrive.

Locorotondo, at 410 m, looks over the valley with a maze of white lanes. Look at the cummerse, houses with a sloping two-layer slab roof, different from trulli. It's one of the Borghi più belli d'Italia, and its white wine, Locorotondo DOC, is made mostly from verdeca and bianco d'alessano grapes.

Martina Franca, the largest, has a walled Baroque centre with monumental gates, the 17th-century Palazzo Ducale opposite Piazza Roma and the basilica of San Martino. Since 1975 it has held the opera Festival della Valle d'Itria in July and August. Try the capocollo, its pork cured meat, and the bombette.

Cisternino, at 392 m, is another of the Borghi più belli d'Italia: a white old town of narrow streets with the Norman-Swabian tower and the Chiesa Madre. It's famous for its butchers with grills, the fornelli pronti: you choose the meat at the counter and they grill it for your dinner.

Ostuni, the white city, stands on a hill about 8 km from the coast, with a walled old town of whitewashed houses and a cathedral with a rose window. In summer it fills up: from about 30,000 residents in winter it grows to many more in August.

How do you get there and get around?

Fly to Bari or Brindisi: from both airports you reach the valley's villages in under an hour by car. The Ferrovie del Sud Est rail network, with a hub at Martina Franca, serves the valley. For Cisternino, public transport is scarce: there are buses to Fasano, which has the nearest train station. With a car you see everything in a few days, because the villages are a few kilometres apart, along narrow roads between stone walls.

What to do?

• Alberobello on foot. Walk round the Rione Monti and the Aia Piccola and go into the Trullo Sovrano, the only trullo with an upper floor, turned into a house-museum: €2.50.
• The Grotte di Castellana, half an hour from Alberobello: karst caves visited with a guide, 1 km in 50 minutes or 3 km in 100 minutes to the Grotta Bianca. From €22 at the ticket office.
• A tasting at I Pàstini, the winery reviving verdeca, bianco d'alessano and minutolo between Locorotondo and Martina Franca: vineyards, cellar and wines in an hour for €15, by reservation and on weekdays.
• Locorotondo, its cummerse houses and the viewpoint over the valley.
• Baroque Martina Franca: Piazza Roma, the Palazzo Ducale and the basilica of San Martino.
• Ostuni, the white city, with its Gothic cathedral at the top of the hill.

Where to eat?

In Locorotondo, Bina serves Apulian cooking with the day's fresh pasta under 18th-century vaults, and opens on Sunday lunchtime. In Ostuni, the Osteria del Tempo Perso, next to the cathedral, serves Ostuni cooking in a 16th-century oven cut into the rock. For a special dinner, Il Poeta Contadino, in Alberobello, has been high-end Apulian cooking since 1977.

Where to sleep?

In a restored trullo, to try it, or in a masseria, one of the old fortified farms in the Ostuni countryside and the valley, many converted into places to stay. If you travel without a car, better in Martina Franca, which has a station and is the biggest village.

• Trullidea, an albergo diffuso of seven trulli in Alberobello's Rione Monti, from €160 a night.
• Masseria Il Frantoio, a 16th-century farm with thousand-year-old olive trees and a pool in the Ostuni countryside.
• Park Hotel San Michele, a hotel with a park, summer pool and free parking within walking distance of Martina Franca's centre.