The Verdon is the river that made Provence famous for the wrong reasons. Everybody knows the Gorges du Verdon — the turquoise water, the 700-metre cliffs, the kayakers and the tourists and the coach parks. That is the lower river, downstream of Castellane, and it is not where you go fishing. The trout water is the upper Verdon, which rises at the Col d'Allos at 2,250 metres and runs south through Colmars-les-Alpes and down towards Castellane before everything changes character and the gorges begin. This upper stretch is classic high-Provençal trout water: Jurassic limestone bedrock, cold clean alpine water, wild brown trout that fish exactly the way a limestone river ought to fish — clear enough to stalk, quick enough to punish a sloppy cast, hatches that are short and intense and a joy when you catch them right. The best fishing is around Colmars and upstream, above the reservoirs. May through early September is the window; the altitude keeps the river cold long after the Cévennes rivers have given up. Fine tippets, small CDC dries, and the kind of careful wading that the turquoise water demands because you can see every stone — and so can the fish.

• Limestone