Sometimes strangeness awaits you through a door you've always passed by on the way to work, a little byway whose name you always knew but that you'd never taken.
We pass through Boncourt every time we drive to Anet. We've known about the Vallé des Cailles - a local nature reserve - for ages, but never bothered to explore. Then last week, the sun finally came out after days of lowering gray skies, and we decided to go for a walk.
The other side of Rouvres, where we've often walked, there are chalk downs with extensive views, long lazy slopes above the valley of the Avre and its villages. Everywhere you see the slate spires of village churches or isolated chapels.
But from the moment we entered the ghost orchard, a raised platform of dead apple trees, barkless and whitened by time, we realised the Vallée des Cailles was different. From the moment we turned a corner, and we could no longer see that acute junction where the road from Bu and the road from Rouvres join, we were in one of those hidden folds of the landscape that seems to take you away from all the places you know - from which you can't hear the noise of the traffic, or see the familiar landmarks.
The Vallée des Cailles is so called from the 'cailles', the flint nodules that are found in the fertile land of the valley bottom. The word might come from 'caillou', a pebble, or from the fact that the stones cluster as thickly as quails (cailles). In the ploughed land, I found a perfect fossilised sea urchin; when I got it home and cleaned it up, I could see fine details, the base of its spines, even the reticulations of its shell, their impression caught in the hard flint.
As soon as we'd turned the corner from the ghost orchard, we found ourselves walking the fringe of the forest; tall, straight oaks on one side, the fields of the valley bottom on the other. On the whitened slopes of the opposite side of the valley fell the long shadows of the forest trees, bristling grey patterns on the frosted furrows. Below, the bare thistledown on the creepers that edged the fields caught the sunlight, glowing white.
Further up the valley, you enter the forest, with its long, straight forest drives, and sudden steep ascents and descents. Each sector of forest seems different; one part with young coppices, slender branches rising straight up or fanned out gently from a single trunk. Here the light was crisp, the forest opening and welcoming. Later on, older trees darkened the forest floor, their trunks massive, their heads gnarled, and huge brambles reared arches across the path.
It was almost silent in the forest; but whenever we stopped, we could hear rustling around us, little scurries and sudden starts.
Coming back, we took the bottom of the valley; another world entirely it seemed, long and level and open, the ruts in the track filled with icy puddles, the forest black and forbidding on one side, gentle and welcoming on the other. And yet you couldn't see out of the valley - couldn't see the houses of Boncourt, or the road, or a hill beyond the immediate crest of the slope. It was a perfectly enclosed world, silent with frost in the pale light of winter sun.
Finally, as we were coming back to the village, we saw the first walkers we'd passed all day; two French ladies out with their three tiny terriers, smart little creatures I suppose before they'd started their walk, but now bedraggled, wet, and filthy with mud. The smallest had to be picked up and towelled dry.
I've done a lot of walking around Eure-et-Loir, but this is a special walk. It's not in the guides, it's not on a GR route (though it's an optional extra on the GR22 from Paris to Mont Saint Michel), even the local tourist office won't tell you much about it. But if you're a hiker, and you're anywhere nearby, the Vallée des Cailles is a rather special seven or eight kilometres.
Reaching the Vallée des Cailles: Coming into Boncourt from the direction of Rouvres, take the road that forks back and left about a hundred yards after the village sign. (You can park along here - alternatively, there's a car park in the village opposite the church; park there and walk back, it's not far.) Keep along the track till you find a sign for the 'boucle', a 4 km loop. The walk can easily be extended into the forest, and if you care to walk a much larger circle, you can walk all the way round, through Anet and then back up the Eure valley.