A fragment of Italy way out in the Mediterranean? While Sardinia is a part of Italy, it is very definitely apart from it - geographically, culturally and linguistically.
"What there is in Sardinia there is not in Italy; nor is there in Sardinia what there is in Italy." Those were the words of a visiting Jesuit priest in the 18th century, and they still hold true today. The Mediterranean's second-largest island is marginally closer to Africa than the Italian mainland, while the southern tip of Corsica, which belongs to France, is just 12km across the Strait of Bonifacio.
The letter "x", rarely used in Italian, makes frequent appearances in the many Sardinian dialects, and three out of five inhabitants in the north-west port of Alghero speak a form of Catalan - a throwback to Sardinia's long period under Spanish rule.
It's not surprising, therefore, that Sardinians routinely refer to Italy as il Continente, and regard the mainlanders as belonging to a different breed, although greatly improved transport links in recent years have made them feel much less isolated from both Italy and the rest of Europe than they once did.
The main attractions? The combination of its peerless Mediterranean climate - freshened by strong sea breezes that can spring from nowhere on the calmest of days - its clear, turquoise waters, and its multitude of white, sandy beaches along 1 900km of coastline, make Sardinia the classic summer holiday destination, attracting backpacker and big spender alike.
But it has much more to offer than beach-life. From the mysterious Nuraghic people, whose megalithic towers have survived virtually intact for more than 3 000 years, followed by the Carthaginians and Romans, the Pisans and Spanish, one invading power after another has left its distinctive mark, in bustling towns and remote plains, hilltops and nearby islands.
Sardinia's interior mountain region, a sparsely populated wilderness of jagged crags and deep gorges, offers some of the best hiking and caving in Europe, and remains as DH Lawrence found it in 1921: "A savage, dark-bushed, sky-exposed land".
In the west, the island contains an area of near-desert, inhabited by a unique, indigenous breed of wild horse; in the north, a valley of bare granite has been sculpted by wind, sea and time into a landscape resembling the surface of the moon; in the south, its salt lagoons attract a phenomenal volume of birds, breaking their journey between Europe and Africa; and in its capital city, Cagliari, the ancient and modern worlds are pleasingly conjoined along one of the Mediterranean's most eye-catching waterfronts.
Within a relatively small landmass, Sardinia offers a bit of everything.
Cagliari, a city of less than a quarter of a million people, still has some way to go to live down its reputation - mainly promulgated by mainland Italians - of being a provincial backwater, scarred by the Allied bombing of World War 2 and the post-war construction, with minimal landscaping, of giant petrochemical refineries.
In parts, it has a neglected air; too many walls and buildings are splattered with graffiti, but Cagliari has many charms to set against its pockets of unsightliness.
The city is built on seven hills, providing numerous lofty promenades and viewpoints. Its surviving bastion wall, two medieval watchtowers and imposing cathedral occupy a superb position overlooking a wide bay, with a shimmering lagoon and a pale blue mountain range in the distance.
Below them, leading to the seafront, are elegant 19th-century streets decorated with jacaranda trees, and running alongside the harbour is the magnificent palm-lined promenade of the Via Roma, with swish department stores and cafes shaded by colonnades.
Culturally, there is enough to keep you absorbed for an afternoon or two. The key venues are all loftily perched in the Castello district, amid the ancient walls and walkways that gave the medieval city an air of impregnability.
The facade of the 13th-century Santa Maria Assunta Cathedral has endured several facelifts, but is worth visiting for its collection of religious artworks and immense stone pulpit.
Also of interest is the Torre di San Pancrazio, one of two soaring, defensive towers built by the Pisans, and the National Archaeological Museum - one of four museums in a modern cluster - which contains all you need to know about Sardinia from prehistoric times to the Romans and Etruscans.
Since this period embraces the entire Nuraghic period, of which no written record exists, the two floors of delicately worked bronze figures and ceramics are as close as you'll get to a sense of their art, crafts, and what they might have looked like.
The museum opens from 9am-8pm every day except Monday; admission E4, English-speaking guides are available, varying their charges according to the size of the group they're showing around.
Cagliari's partially restored Roman amphitheatre, built into a hillside west of the city centre, stages regular musical and theatrical performances on summer evenings. Even if you don't entirely understand what's going on, the views of the city walls to the east, and the setting sun to the west, will stay long in the memory.
Hardly a week goes by in Sardinia without one major festival or another. Many festivals are religious in origin, but others celebrate annual events such as the harvest, or the tuna fish catch on the island of San Pietro.
The most important Festa takes place in Cagliari in early May, commemorating Saint Efisio, Sardinia's patron saint.
Efisio, a Roman commander, offended his employers by converting to Christianity, and was beheaded as a suspected traitor in AD303. But the main reason he's venerated is that he's believed to have answered the islanders' prayers to rescue them from the plague in 1652.
In almost every year since, a bizarre ceremony has been held by way of giving thanks. On May 1, people arrive from all quarters dressed in the traditional costumes of their region to accompany the saint's effigy - on foot or horseback - as it's carried in a gilded ox cart through the city to the former Roman capital of Nora, where the execution took place.
That evening, Cagliari stages shows and folk music concerts, and three days later another colourful procession returns the effigy to Saint Efisio's church in the capital, and lays it to rest for another year.
The most fashionable resorts? The Costa Smeralda has been one of the premier haunts for Europe's beautiful people on vacation since a consortium led by the Aga Khan developed a 50km strip of the north-east coastline in the 1960s.
The densely wooded hills overlooking bays, coves and some outstandingly beautiful beaches that can only be reached by boat, contain some of the most exclusive villas and hotels in the Mediterranean.
Silvio Berlusconi owns several properties here, and visiting luminaries have recently included Bill Gates, Roman Abramovich, Rod Stewart and the Blairs.
Every property in the resorts of Porto Cervo and Cale di Volpe - their marinas bulging with superyachts, their shopping centres with frighteningly expensive boutiques - has to conform to a central design plan intended to harmonise the buildings with the environment, using local granite and limestone finished in subtle pastel tones.
Whether the faintly Moroccan style of architecture enhances or blots the landscape is open to question, but what's not in doubt is that the Costa Smeralda's season lasts barely three months, whereupon it reverts to being a well-manicured but somewhat chilling ghost town.
It helps if you have your own transport, because there are numerous fascinating places.
At Nuraghe Losa, lying in splendid isolation within sight of the main road (SS131) about 30km north-east of Oristano, a winding stone stairway gives access to two of the original three storeys of a 3 400-year-old fortress and several ancillary buildings dotted around the site.
Buy an entry ticket at the adjoining cafe or the site's small museum, which opens between 9am and sunset, and let your imagination roam undisturbed.
- For more information, visit www.nuraghelosa.net.