A transnational border river between Spain and France, draining the western Pyrenees with classic mixed-geology spate character. In modern practical fly-fishing terms, the Bidasoa should be treated as a trout-and-sea-trout river with strong heritage-salmon identity rather than as a realistic salmon-chasing destination. The 5-hour response time to rainfall still creates excellent post-spate windows, and the lower and middle sections around Bera remain the key structured water.
In the steep, often pressured Atlantic rivers of the Basque Country, trout opportunities centre on spring olives and other up-wings when flows and colour briefly line up, with caddis and buzzers helping to sustain sport into early and mid-summer, and terrestrials from grassy, wooded margins adding surface food in quieter, recovering reaches.
- Mixed

