There was no secret map, no requirement to drink snake's blood and no sign of ruthless pot-growers. Just a middle-aged Englishman pottering along the cliffs in unsuitable clothing with a picnic of six BabyBels, a tomato and a can of 7-Up in a plastic bag, when - wham! - there was the world's most perfect beach.
I can identify it, tell you that it's called Plage de Pertusato, give you the grid references if you like, because Corsica isn't exactly undiscovered. But on a blazing day in late September, this earthly Paradise was dotted with only four drowsy young Germans and a family of Mum, Granny and four scampering kids from Bonifacio.
Their incredible town, cantilevered out on its eroded limestone prows, gleamed three miles away, the rock striped with grey and honey as though Hornblower had beached a couple of frigates for a spot of whitewashing. Slithering down through the maquis in my suit trousers and sweat-drenched shirt (it was an afternoon off from a conference), I was already glutted with beauty. Not just Bonifacio, but a curtain-raiser to The Beach in the form of a narrow, deserted defile to the previous inlet, through junipers and past abandoned Genoan cannon embrasures.
There was no sand there, and swimming in the water, whose clarity above the limestone pebbles turned the blue sky into turquoise and lapis lazuli, was a nervy affair, with the swell heaving up against the lip of the rocks and sea urchins waiting if you misjudged your footing. Pertusato has the bonus of a soft fringe of white sand, along with an almost-islet where the rock has been shifted on its side by some crunch of tectonic plates, leaving a scrabbly path to the top where you perch above a precipice and incredulously take in the view.
It is, to be practical, mainly a view. There are no tavernas here, little shade and the Bonifacio family kindly warned me that what looked like two sandwich bags flopping on the ripples were jellyfish with lazily-drifting stings. The walk to Pertusato is long and hot and most normal children under 10 would probably arrive in tears. But The Beach is a place, like Alex Garland's invention in Thailand, which will stay in your imagination.
Its more practical counterpart in Bonifacio itself is a tiny pair of sandy crescents down a zig-zag of cliff steps, where another scramble takes you to an unforgettable ledge, just above the waves in calm weather and far below the overhanging rim of the town. This is a very dangerous walk in rough seas, and an Italian family was swept off and drowned two years ago. But worn iron stanchions and bits of safety cable show you the way in normal conditions, along with a ghostly flight of rock steps and a squeeze between limestone layers so tight that you have to crouch to avoid clocking your head.
The adventure ends at the celebrated King of Aragon's Steps, another giddy ladder up the cliffs, but one with an unclimbable spiked gate at the bottom and a tourist entry charge at the only official entrance, in the Old Town at the top. This makes the descent a little tamer, but is well worth paying for another, disbelieving view of 16th-century houses on their white and caramel rock shelves which one day will collapse into the sea.
There is no way up to the Old Town and citadel of Bonifacio that fails to astonish, whether you take the polished setts of the military ramp which lead through a dark barbican with double portcullises, or the steep flights of stairs - le chemin de ronde - inside the hollow defensive walls. Closing two gates would seal the entire place off, and did through epic sieges in 1420 and 1553. There are still strong distinctions between Old Towners, with their dialect, dress and other unbroken links to the Genoan garrison which survived so perilously here, and the people of the Port below, whose ancestry is more purely Corsican.
The Port is standard Mediterranean perfection, with harbour cafés, yachts bobbing in the wake of the Sardinia ferry and the citadel rising grandly behind like its counterparts at Calvi in the North or Corte, the old island capital in the mountains. But the Old Town is the more exciting place to stay, either at one of three modest hotels - Le Royal, Genovese and Santa Teresa - or a chambre à louer in the stone tenaments which interconnect and tower above the network of narrow streets so steeply that the first floor, in many cases, is reached by a ladder.
Squeezed into the narrow space between the fortress walls (although carefully leaving room for a boules piste), the Genoans could only build upwards. Their tower blocks - ornamented with delicate coats of arms and carved window lintels - reach eight, nine and even 10 storeys high. The 16th-century Corsican shepherds must have viewed the place as we do Manhattan.
The best guide to Corsica, Dorothy Carrington's Granite Island, credits Bonifacio with a "supernormal intensity in every arch, campanile, doorway or moulding", outshining the finer architecture of more famous cities because of its context of a hostile wilderness. That is still very much there in the lethal channel between the town and Sardinia (only eight miles away) and the rock-strewn maquis leading up to the needle-shaped mountains of Bavella.
But the town also, miraculously, has an undiscovered and in places almost neglected air, familiar to me from a magical period as a reporter in Bath in the early 1970s, just before everything was sand-blasted, English Heritaged and quadrupled in price. Partly because of the recent withdrawal of the Foreign Legion, Bonifacio's Old Town has unexpected, ghostly sections prowled by cats and windy stretches of fennel and rosemary clinging to recent ruins.
After a happy siesta in several cafés and a desultory exploration of the sites (St Helena's fragment of the True Cross in the lovely church of St Dominic and the neighbouring houses where Charles V and Napoleon stayed) I strayed into one of these wildernesses, the cemetery on the tip of the headland where Sardinia's mountains rise dreamily out of the seahaze. Here, the old Genoan families and their descendants sleep in little miniature mansions, vividly painted in a way that suggests an admirable belief that the next life is going to be good fun.
Notices appealed for quiet, vainly in my case thanks to an unwise souvenir - a little carved box with two wax-paper birds inside which tweeted when you opened the lid. En route to the cemetery, they had started chirruping and no amount of shaking and clenching would shut them up.
"It is the light which activates them, M'sieur," the young woman back in the shop explained, amid giggles as we unwrapped the muffled tweets from more of my plastic bags. The light is another wonder of this lovely town and its necklace of beaches; and in the end it took three plastic bags, a green dustbin liner and a swatch of embroidered ebony cloth, compliments of the Madamoiselle, to silence the irrepressible birds.
