Talybont Reservoir

Talybont sits in a heavily wooded steep-sided Brecon Beacons valley — three hundred and eighteen acres of wilderness reservoir, wild brown trout only, fly only, and the kind of approach where the path through the conifers does the work of convincing you you're going somewhere proper. The opening date is 20 March; the season runs to early October. Day tickets are catch-and-release on the Passport, capped at thirty rods, which on a water this size means you'll mostly hear birds. Buzzers from April, with the kind of evening rises that justify staying out past common sense.