Italy's neglected heritage sites are being sponsored by fashion brands

We had half an hour before the concert began, a music critic friend and I, in an obscure Umbrian hill-town I'd vaguely heard of but never visited before. After wandering through medieval streets of warm, terracotta-coloured brick, we found ourselves in the irregular, sloping main square in front of a higgledy-piggledy cathedral. We pushed rather tentatively at the wooden doors, not knowing if this ancient place of worship would still be open at nearly 8pm. It was.

In front of us, above the main altar, was a painting of startling chromatic magnificence, not a painting either of us culture vultures had known existed, but one worth making a journey for, perhaps several journeys. The Madonna in Glory – with the protector Saints Gervasio and Protasio, Saints Peter and Paul, a couple of angels, a few putti and the pennants of the city for good measure – glows with the extraordinary brightness of the colours the artist applied to the wooden panels in 1514 (the painting is signed and dated).

We spent many minutes transfixed by this masterwork. The Madonna in Glory is a symphony of blues and reds; the red of the Madonna's dress and the blue of her cloak rhyme with the blues and reds of the tunics worn by the two absurdly youthful and beautiful protector saints, and the vermilion of the proud city banners. There's a freshness about the altarpiece which belies its 500 years, as if the high noon of European painting had been preserved, forever young.

The artist is Pietro Vannucci, known as Perugino, born in this town, Città della Pieve, around 1446. Perugino is of course in the second division of Italian renaissance artists (but what a league that was), and Città della Pieve in the second or even third division of central Italian hill-towns. Surely if Città della Pieve was in any country other than Italy, the lovely and well-preserved medieval settlement would be on any number of tourist itineraries. And incidentally, the Madonna in Glory is not even the best-known Perugino here; that is the Adoration of the Magi in the Oratory of Santa Maria dei Bianchi.

Italy has the highest number of Unesco World Heritage sites of any country; it also has the highest number of world "cultural" sites, at 46. These figures do not convey the staggering wealth of Italy's heritage; there are 20 national museums in France, but 400 in Italy. Italy has between 350,000 and 400,000 protected buildings, compared with 25,000 in France. Some reckon that Italy contains 70% of the world's cultural heritage.

This overwhelming richness is treated with staggering indifference by the Italian authorities. Every year bits of the heritage crumble to dust or disappear. Recent examples include the collapse of the House of the Gladiators in Pompeii and chunks of marble falling off the Colosseum and the Trevi fountain in Rome.

"Italy has never spent enough on culture," according to Roberto Cecchi, Under-Secretary at Italy's culture ministry. That may be an understatement; the Italian culture budget shrank by a third under Berlusconi and a recent report stated that Italy only spends 0.2% of its GDP on culture compared with France's 1%.

There is currently an attempt to make up the shortfall using private sponsorship. Shoe chain Tod's contributed €30m to clean up the Colosseum. Fendi is paying €2m to restore the Trevi fountain and Diesel have given €5m to help repair the Rialto bridge in Venice.

You may bridle at the idea of the Tod's Colosseum but perhaps the means don't matter so much; the important thing is to preserve and protect what may be an embarras de richesses to the authorities, but is a wonder and a glory to all humanity. What is so special about Italy's heritage is that so much, like Perugino's Madonna, remains exactly where it has always been. May that ever be so.