Half-way across the miraculous Ponte delle Torri, a stern stone viaduct that stomps from the summit of the town of Spoleto across to the Umbrian hills, I paused and gazed down into the sort of valley that puts the V in vast and vertiginous.
And I thought. Of Luton.
Thanks to the new breed of low-cost airlines that are based at the Bedfordshire airport, I mused, it is now much easier to peer down into the deep Tessini river valley. Here's how. Debonair's new route takes you non-stop from Luton to the Umbrian capital, Perugia. The trouble is, for the return journey you have to go via Rome, 100 miles to the south. Since the airline will charge you the same price whichever city you fly home from, you might as well turn this to your advantage. Buy an "open-jaw" ticket and set a carving course through the heart of Italy. But first you have to find your way out of Perugia airport. If you think Luton is diminutive, wait until you see where your plane is landing. With a bit of luck, the final approach will be from from the south. The planners have taken advantage of a brief respite in the Umbrian hills to plant a runway on the plain between two miraculous hill-towns - Perugia itself, and Assisi, each clinging to its peak like a wayward sandcastle. You soon come down to earth. Adamo Giuglietti airport is the size of a shed: a big, bright and recently refurbished shed, but a shed none the less. The arrival of the Luton service has not triggered a bus service, so you may need to rent a car (a good option, considering what's in store) or take a cab. But once along the absurdly grand approach boulevard and through the stout stone gates, which way should you go? Turn right, and in front of you looms Umbria's capital. Perugia is one of Italy's finest cities - a feast of Renaissance extravagance spilling over a series of hills. It feels a truly three-dimensional place, with a Machiavellian system of stairways and viaducts to help you thread your way under, around and across a city that seems designed for intrigue. Beyond it, you could subside to the shores of Lake Trasimeno. Yet to adhere properly to the spirit of the open-jaw traveller, you really should turn your back on Perugia and begin the pilgrimage to Rome by heading left from the airport, crossing a tributary of the Tiber, and aiming for Assisi. Now is the worst and best of times to visit the last resting-place of St Francis. Two years ago, the restless earth rumbled and shook his basilica with hellish force. In the earthquake, four people died when the roof of the upper church caved in. Today, a jumble of scaffolding props up the bruised but beautiful building. You can pick your way through the metallic maze to the simple tomb of St Francis, but, at the moment, the extravagant frescos in the upper church are undergoing painstaking restoration. While the art of salvage has got under way, an Italian bank has taken over a chapel opposite, and installed a neat exhibition that shows, in the nicest possible way, what you're missing - Giotto's dazzling sequence of 28 frescoes depicting the life of St Francis. What you may also miss - but not regret - is the normal consignment of tourists. Until the reconstruction is complete (like most projects in Italy, it is promised for "some time in 2000"), many of the tour coaches will bypass the place. So you can freely clamber up the main street from the basilica to the piazza in relative solitude, enjoying a repertoire of architecture that only Italy can deliver, a meander from Roman to Renaissance and beyond, all of it on a human scale. Talking of tourists, you probably know dozens of people who have visited the Trevi Fountain in Rome. …