Vive Le Loir

What a difference a gender swap and the loss of a final "e" can make. Because Le Loir, a little-known river valley that runs parallel to La Loire for close on 100 miles, is a very different kettle of fish.

It rises near Châteaudun, splits into four when passing through the medieval walls and mills of the county capital of Vendôme, glides gently beside glorious châteaux and quiet market towns, before joining up with its more famous neighbour just short of Angers.

Even at this final stage it is no larger than the Thames above Oxford, with wooded hills and meadows dropping down to its quiet waters. This makes for wonderful walks, riding and canoeing — better, in my opinion, than the broad downstream reaches of La Loire, with its sandbanks and islands and flood plain protected by dykes.

When messing about on Le Loir you can rest assured that on this river you are not downstream from one of France's larger nuclear power stations. And while La Loire can boast more royal châteaux (though most are on smaller tributaries), these Unesco heritage sites draw hordes of tourists in summer and school trips once term starts.

Life is altogether more laid-back on Le Loir. Even its prettiest villages such as Lavardin, nestling beneath a ruined castle where goats graze the turf, are delightfully free of postcards-and-tat outlets. I wandered its narrow streets up to the collegiate church of Saint Genest, whose wonderful series of wall paintings date back to the 12th century, before climbing the steep Rotte aux Biques (Goats' Way) to a row of cave dwellings cut into the tufa cliffs.

The façades of these troglodyte houses look like rustic cottages but within you enter a rock-hewn world very different from any house you're likely to have stayed in. They keep cool in summer, warm in winter, and the few that are rented out — both in Lavardin and the nearby village of Trôo — make for a distinctive self-catering holiday or B&B experience.

Descending the narrow path to the main village I stopped at Lavardin's "temple of gastronomy", the Relais d'Antan, whose gardens drop down to the river and whose specialities include lasagne de langoustines and grilled sandre (the local fish) au beurre blanc, accompanied by a fruity Jasnières or Côteaux du Vendômois.

Some of the best stretches of river for kayaking and canoeing are just downstream from here, near Montoire. And if it's châteaux that you're after, Le Loir can boast a string of them, having been for centuries the front line between the rival Angevins, Plantagenets and French kings.

My favourite is the Château du Lude, which has guarded this stretch of the Loir for 1,000 years with its massive towers and moat. Surrounded by lovely rose gardens and parkland, what distinguishes this from the formerly royal and now state-run Loire châteaux is that it is still privately-owned.

Scattered among the 18th-century furnishings I noticed a photo of the Queen Mother, a friend of the previous châtelaine, while the medieval kitchens display all the latest mod-cons of its most recent refit — 100 years back. Most Renaissance Loire châteaux were hunting lodges, and for a feel of that visit the privately-owned Château de Champchevrier, with its pack of hounds occupying pride of place beside the gateway. The British Embassy in Paris fled here in 1940, its owner told me, so the British are always welcome.