Trail of the unexpected

We tend to think that the pursuit of the Holy Grail was a British endeavour, involving everyone from Sir Galahad to Monty Python. Certainly, the locations of King Arthur's legendary exploits are well signposted in the UK, notably at Tintagel in Cornwall. Yet across the Channel, Breton minstrels set their versions of the sagas of Merlin and the Knights of the Round Table in woodland just outside the modern-day city of Rennes.

There is even a scenic tourist route that winds its way around the ancient forest of Broceliande, allowing the cyclist, walker or motorist to visit a succession of historically elusive enchanted valleys, magical stones and fountains of youth.

Take for example, the Val Sans Retour, the valley of no return, where unfaithful men were entrapped by Morgane, Arthur's embittered fairy half-sister. Late one afternoon I left the picturesque village of Paimpont, at the heart of the forest, and a 10-minute drive following the brown scenic route road signs brought me to the car-park at the foot of the valley. Through the woods I saw a shining golden tree trunk and for a few dizzying seconds thoughts galloped through my head: World exclusive – Holy Grail found near French car-park. I closed my eyes and opened them again. It was still there. It turns out that the tree, painted in gold-leaf, is a memorial to a devastating fire that destroyed much of the woodland here 13 years ago. Still, it was enough to kick start the imagination.

A gentle path runs from the tree, past a series of tranquil and ever more remote lakes, winding through woodland until eventually the brambles and cliffs begin to close in. It is difficult to address the issue of the Holy Grail without thinking of Monty Python, and I half expected to encounter Graham Chapman's King Arthur accompanied by a dishevelled subject clapping two coconut shells together to substitute for the lack of a horse.

Or perhaps the Knights Who Say "Ni" would order me to construct a shrubbery to ensure safe passage. With the shadows lengthening, I turned back and, by the golden tree, climbed up a blood-red rock for a beautiful viewpoint over the forest and a nearby waterfall.

Back in Paimpont the timing of my walk met with the approval of Tiziano, an Italian druid who runs a souvenir shop in the village. He explained the rock was known as "Merlin's seat", and was where the old wizard would come and watch the setting of the sun. "It is a special time of day," noted Tiziano. "The old light of the sun is fading and the new light of the moon is rising. The border between reality and magic is very thin at that moment. You will see all the little people come out. But you will only see them with your heart, not your eyes."

Imagination is certainly required at some of the dozen or sites. Perhaps it was unfortunate that the forest was in the middle of a three-week drought but the fountain of youth, for example, was little more than a muddy ditch. Nearby, one of Brittany's enigmatic megaliths was said to be Merlin's tomb and has become something of a shrine for devotees. The fountain of Barenton, though, said to be the place where Merlin and the enchantress Viviane first set eyes on one another, was located in a remote dell that was utterly charming.

The point is, I guess, that whether or not tales of noble knights, fairies and magic spells press your buttons, the forest has an undeniable special quality. The light is soft, the silence broken only by the chirruping of finches or the running of water from the abundant springs. The woods recall the New Forest, only with hills, and they retain an age-old sense of pastoral tranquillity. Paths are covered with pine needles that dull your footsteps, while wooded glades suddenly open up to reveal deep and graceful lakes.

Although Sir Galahad is said to have found the Grail somewhere in the forest, the best efforts of the local tourist board have failed to locate it.

A trick of the light in the medieval church of the tiny village of Trehorenteuc indicated how elusive it continues to be. The blending of pagan and religious lore is visible in the stained-glass windows of the church that depict the Apostles sitting at a round table on which stands the Holy Grail.

On a clear day the sun casts a shadow through one of the windows that throws up a shimmering cup shape on the interior wall. Cults have been started over less.

You can sail from Portsmouth to St-Malo on Brittany Ferries (08705 360 360, www.brittanyferries.com), from where Rennes is an hour's drive. Ryanair (0871 246 0000, www. ryanair.com) flies from Stansted to Dinard, a similar distance away. A return train trip from London Waterloo to Rennes by Eurostar and TGV (Rail Europe, 08705 848 848; www.raileurope.co.uk), changing at Lille, costs from £99. Brittany tourist board: 00 33 2 99 78 47 47; www.bretagne35.com