With another six hours to go,I continue,the sound of rushing water below maddening in the scorching midday heat. Having passed waterholes all day,the siren song of splashing and laughter below alerts me to the final waterhole today.
It's brochure perfect,rock-rimmed with turquoise depths. There's just one issue:it's occupied by two young men. And they're naked. But since the water looks so beguiling and they're having so much fun,I call down in French to ask if I can I join them and would they mind putting some clothes on."Allez!"they call.
I shed down to underwear and submerge,the heat ebbing deliciously as frigid water rises and tingles. Suddenly,I'm part of the postcard and we grin at each other with this discovery of paradise.
We continue up the hot rock slabs towards the pass and it transpires the Naked Brothers (Artur and Robin) are from Fribourg,Switzerland,famous for the"moitie-moitie"(gruyere and vacherin) fondue. Most attempt the GR20 with light loads but the duo have packs like Atlas,revealing a mini-supermarket containing their beloved vacherin and dried meats. The Swiss really know how to picnic.
The 710-metre descent to the ski resort of Haut Asco is knee-jarring. Day two has been physical,the challenge I sought,but tomorrow will truly indicate if this is indeed the toughest route in Europe. The cirque makes or breaks walkers,some retreating at the mere sight. We'll see if I earn some trekking stripes,or if by day's end I'm at a bus stop,tail between legs.
On day three,the path traverses pine forests,windswept plateaus,granite passes and rugged alpine pastures with views from snow-capped mountains to golden coastline,plus the highlight,the Cirque de la Solitude.
But not everyone will make it today. One of the Swiss has been vomiting and remains in Haut Asco;a Pole has left with an injured knee.
I walk slowly,hoping the Naked Bothers will catch up,relieving me from facing the cirque alone. We meet on the pass and pause for a picnic,at which they produce vacherin,jambon cru (ham) and Lindt chocolate. The Last Supper.
We're joking but the humour reveals an undercurrent of tension. We're in a dramatic circle of stone pinnacles,the path dropping 350 metres below before rising up the other side. Trekkers crawl down like multicoloured ants,clinging to ladders and ropes,disappearing into the abyss.
We dive in and,immediately,it's fun. Finding footholds and descending ladders is like a game of chess,peaks frowning above and the sea beckoning in the distance. It's a special place,the cirque,wrapped in the folds of the mountain.
It's not so special for a German lady blocking the way,rooted to a ladder and racked with anxiety. Most travel the cirque about 10am and such traffic jams are legendary. But now,after midday,we have the cirque (almost) to ourselves and,indeed,it offers solitude.
No sooner are we down than we ascend again,another enjoyable physical obstacle course. At the top an eagle soars overhead,its effortless glide mirroring my own feeling of freedom.
I leave the Naked Brothers while they break out celebratory beer at Refuge di Tighjetti. I'm keen to stay but my accommodation has been booked 30 minutes downhill at U Vallone,where I find tonight's surprise:a tent.
Day four dawns and it has been a rough night in the foetal position,with socks for gloves,watching the clock spin until sunrise. I assumed the huts would be similar to alps refuges,with blankets and fluffy pillows,and I am travelling light. But this trek is the real,rustic deal.
If yesterday's cirque was great,then today is fantastic,the best yet:a magical universe of cascading waterfalls,numerous grottoes,mountain heights and boulder climbing. It's a shame the Naked Brothers left for Corte and home,convinced they'd experienced the best of the track. The adventure is just beginning.
Descending the pass at midday,more grottoes and more people emerge,this time French and this time in clothes. I join them diving,plummeting into a round pool so deep the aqua bleeds into indigo.
Just before reaching Hotel Castel di Vergio,while concentrating on the track. I run into a wall. In fact,it's not a wall but a two-metre German called Thilo. That night,
I have dinner with him and his friends Dirk and Charlotte.
The next morning,day five,there's a new casualty. Dirk has blisters and he and Charlotte depart for Corte. It's a shame;today is a gift of simple forest walking before entering pastures reminiscent of the Scottish Highlands. It's also where I'm scheduled to descend to the mediaeval town of Corte via Sega,the tour operator's itinerary conclusion.
I pause at the cheese farm turnoff and spy the yellow daub on my pole. Pierre said to follow the stick and it's pointing towards Refuge de Manganu. I abandon plans and continue for another two days until the true halfway point of Vizzavona.
Buoyed by the excitement of spontaneity,I arrive realising that emerging from under the tour operator's wing I'm out in the cold,literally. Even in shoulder season there are more people than beds,hence the tent carriers. But fast-talking Thilo and two Australian couples score me a mattress.
I'll meet the Sydneysiders Hugh and Judy and Richard and Mary-Anne again tomorrow afternoon and,in what seems a common theme of this trip,one of the men will be wearing only half his pants.
Day six and I am over the stones. This hike's difficult status might be awarded for a complete lack of level ground. Every stone in the world has conspired to arrive on this track,which requires utmost concentration. I haven't face-planted yet but my legs exhibit new scrapes and bumps daily and,later,some scarring provides a more permanent souvenir of the GR20 than I would have liked.
At dusk,I stumble upon Team Australia,sitting on tiny Refuge de Petra Piana's balcony,bemusedly watching the unfolding bedlam. The 24 beds are full and a group of 17 has dropped in. Donkeys carrying their luggage arrive,adding to the chaos and,amid the drama,Richard returns from a jaunt,slightly traumatised. He's been attacked by a cow,who tossed him into bushes,ripping his pants.
I'm ousted from the refuge,offered the kitchen floor,then promoted to the attic. For the second day in a row,I've lived on goodwill and good luck.
The final day to the hamlet of Vizzavona is a stunning descent through forest alongside a stream,inviting a final plunge. Lower down,hordes of day trippers swarm waterholes and it's clear I'm back on the beaten track.
I can't help feeling I'm holding on to a secret they will perhaps never experience,the interior of Corsica,the merciless yet bountiful mountain tracks that give and take in equal measure and will leave a lasting mark (my legs confirm) of this wild and unsung Mediterranean jewel. Is it the hardest trek in Europe? Well,I haven't done them all but it's certainly,so far,the best.
The writer was a guest of UTracks.
Trip notes
Getting there
Swiss International Air Lines has daily connections to Nice from Sydney. Ferries and Air France flights connect Nice and Calvi,close to the northern starting point of Calenzana.
Walking there
UTracks has self-guided,seven-day GR20 (north) trips priced from $1390 a person. Includes on-the-ground luggage transfers,most meals and six nights'accommodation. 1300 303 368,utracks.com.
More information
corsica.forhikers.com/gr20,www.le-gr20.com/gb.
GR20 tricks and tips
1. Snow falls from October and the route can have snow in June. Avoid peak season and blistering hot July and August;September is the ideal time to go.
2. Book ahead and carry paper printouts of bookings — some huts require them. Not up for the northern GR20? Try the more gentle southern half.
3. Attempting French (or even the Corsican dialect) will win you friends (and beds) — a little of the local lingua goes a long way.
4. Cash is king;there are no ATMs along the GR20 unless you deviate to Corte and few,if any,huts accept cards.
5. Get into the local cuisine. While not famed,the brocciu (goat's cheese),cignale (wild boar) and liqueur de chataigne (chestnut liquor) are winners.