Under dark grey skies and accompanied by a soundtrack of vomiting children on the ferry from Quiberon, our trip to the islands of southern Brittany did not begin very romantically. I certainly didn't feel like I was about to discover somewhere exotic. Belle-Ile-en-Mer, despite its simple, come-and-get-me name (translation: "beautiful island in sea") and its proximity to British shores, is almost unknown to British tourists. The clouds were blown away as we entered the port of Le Palais; the sun blazed down on the island's capital and largest town (with a permanent population of 2,500), and our boys' faces lit up. This was not the bleak, uninhabited rock they'd been expecting. There were shops! There were restaurants and bars! There were hundreds of yachts! There were long, sandy beaches! However, given that we had only three days to see three of the 15 Iles du Ponant that are scattered all around the Breton coast, there was no time to linger in this pretty, lively town.
We drove from Le Palais to the northern tip of the island. The celebrated French actor Sarah Bernhardt had a house here - it is now a museum - and you can see why she came here to escape the pressures of life in Paris. With its jagged cliff-faces and wild stony beaches, the Pointe des Poulains is bleakly beautiful. We got caught in a rainstorm while there, and had to take refuge inside a cave.
When the sun came out again, we drove to the beach at Donnant. Having spent the previous two weeks on beaches at St Malo and Weymouth, Donnant came as a pleasant relief. Whereas they had been packed with windbreaks and parasols, this was the seaside in its original, Edenic state: a vast, open stretch of sand and sea, punctuated only by rocky coves and inlets. It was also devoid of other tourists, apart from a handful of sunbathers huddled in sheltered coves and a few surfers who emerged from the waves covered head to foot in iridescent foam. This looked so much like washing-up water that I thought it must be some form of pollution, but everyone on the island assured me the effect was natural.
We ate lunch in the small town of Bangor and walked to a lighthouse - climbing its 200 steps and looking out on a gorgeous (and vertigo-inducing) panorama. Another half-hour walk took us to the Aiguilles de Port Coton, a series of strangely shaped rocks in the sea which have been painted by Monet among others. I could happily have spent an hour or so contemplating them, but we reached the cliff-edge at the same time as a large group of Parisian tourists, whose chatter and shutter-clicking made meditation impossible.
To be perfectly honest, August is not the ideal time to visit Belle-Ile. Though it is nothing like as overcrowded as Ile de Ré, for example, it still seems a shame to experience a place of such natural tranquillity at the one time of the year when that tranquillity is disturbed. You should go now, or in October - or in spring or early summer. Then, not only will you find the beaches empty, but the roads will be free of learner-cyclists, and you will also be able to cross the pedestrian bridge into Le Palais without waiting 20 minutes while a queue of yachts cruises into the mast-packed harbour.
As traffic jams go, however, this one was quite pleasurable, thanks to the warm, orangey evening sunlight that covered the white and pastel buildings of the town. It felt almost Mediterranean as we sipped aperitifs on the terrace of a bar and looked forward to a dinner of galettes (savoury Breton pancakes) and cider.
Around midnight we went back to our hotel - the Clos Fleuri, which is a 15-minute walk from Le Palais. This - along with the Hotel Désirade, near Bangor, where we stayed for our third night on Belle-Ile - changed my opinion of French three-star hotels for good. Before, I had always found them to be almost stuffily bourgeois; the kind of places where everyone stares at you in cold silence if one of your children laughs during breakfast, and where the floral wallpaper has not been changed since 1972. The Clos Fleuri and the Désirade, however, are part of the new generation of hotels on Belle-Ile, run by owners in their 30s or 40s who have discovered the island as visitors and fallen in love with it. (Half of Belle-Ile's population falls into this category in fact - even Leena, the chief tourist officer, is Finnish.) Anyway, the Clos Fleuri, like the Désirade, is brightly and stylishly decorated, more like a boutique B&B than a traditional hotel, and with the same level of friendliness and personal service.
The next day we drove to the port of Sauzon, sweetly calm and postcard-perfect in the morning sunshine, and from there took the boat to Hoëdic. With no cars (apart from a few emergency vehicles) or even bicycles on Hoëdic, the only way to explore it is on foot. This news did not thrill our children, whose legs were, according to them, "about to fall off", but it was really no hardship as the island is only 2.5km long and 1km wide (less than that at high tide) and the permanent population is only 111. It is also the sweetest-smelling place I have ever been - the little yellow and white flowers that cover all the rocks emitting an intoxicating fragrance of honey.
There is a 19th-century fort in the middle of the island, with exhibitions of paintings and sculptures, and a village with three cafes, two of which - be warned - stop serving at 2pm precisely, but all the real wonder lies beyond this small centre. There is nothing much here - just beaches and grassed-over dunes and little pine forests - but it is a beautiful, peaceful nothing. We went swimming in the sea, very briefly, and we walked around. It was so lovely, the boys forgot how tired their legs were. And the sun shone all day - or at least until we got back to Belle-Ile, at which point it began to bucket down.
We were meant to go to another nearby island, Houat (pronounced like René in Allo, Allo, saying "what"), the next day, but the glowering skies and gale-force winds and our almost-dead children persuaded us to stay on Belle-Ile instead. By all accounts, Houat is like Hoëdic but with bicycles and even bigger beaches, so if it's sunny you should definitely make the trip. But in the rain, such tiny islands are a 12-year-old boy's vision of Hell, so we ate croques monsieurs and explored toy shops. And then, best of all, we drove our bags to the Hotel Désirade and swam in their heated outdoor pool.
Fully recovered, and with the sun shining again, we went to the island's fourth and most southerly town, Locmaria, which is pretty but unremarkable. A short walk, however, takes you to Port Maria, which is not a port at all, but a glorious little beach, sheltered on both sides by very climbable rocks. There were more bathers here than at the Plage du Donnant, but it was still idyllic: the sea was almost warm, and the whole late-afternoon scene had a feeling of calm, protected contentment.
That day, we'd asked a couple of fishermen where the best fish restaurant on the island was - and discovered, to our joy, that it was the restaurant belonging to our hotel. Even with a French-English poisson glossary, deployed by the friendly waitress, we weren't entirely sure of the names of the fish we were eating, but all four of them were delicious, so it really didn't matter. And the boys had a great evening watching the lobsters fight one another in the glass tank next to our table.
On our final day we took the boat back to Quiberon, and from there drove an hour northeast to Vannes, where we caught the boat to the Ile d'Arz (pronounced, depending who you ask, either like the French word for "art" or like the old drunk priest in Father Ted saying "Arse" - take your pick). Unlike Belle-Ile and its neighbours, the Ile d'Arz is not really in the Atlantic at all, as the mainland bends around it in both directions, creating an enormous bay. We went there at low tide, which revealed long vistas of mudflats and beached fishing boats, and the boys had a fantastic time swimming in the warm, muddy, saltwater pools left behind by the retreating sea.
We hired bikes and this proved the perfect way to see the island. Cars are not forbidden on Arz, but we saw only three of them during the five hours we spent on the island. It was less easy to escape the other tourists though. Arz is so desolately beautiful that you want to have the whole place to yourself, but in August this is more difficult. It's not impossible though - the trick is to keep cycling. In the late afternoon, having followed a narrow muddy path along the winding coastline, we discovered a part of the island - the Pointe de Billihervé - where, for the first time, we could look around and not see another soul. It was a wonderful feeling. Go there now, and the whole island should feel like that.
· Sam Taylor's next novel, The Island at the End of the World, will be published by Faber in January.
Way to go
Getting there
Brittany Ferries (0871 244 1400, brittanyferries.co.uk) Portsmouth-St Malo crossing for two and a car with a cabin from £290 return. Compagnie Océane (0033 2 97 35 02 00, compagnie-oceane.fr) sails to the Iles du Ponant.
Where to stay
Hôtel le Clos Fleuri (+2 97 31 45 45, hotel-leclosfleuri.com), doubles from €77 pn. Hôtel La Désirade (+2 97 31 70 70, hotel-la-desirade.com), from €137 pn.
Further information
Brittany Tourist Board (+299 361 515, brittanytourism.com). Belle-Ile-En-Mer tourism (+297 318 193, belle-ile.com).