The Nizonne — called the Lizonne on the Charente side of the border — is another Dronne tributary in the Périgord-Charente groundwater country, running south through the bocage from Villebois-Lavalette to join the Dronne near Aubeterre. It is narrower than the Bandiat, slower and weedier than the parent river, and holds wild brown trout in the sort of concentrations that small limestone streams sometimes do when nobody is paying attention. The character is entirely groundwater-fed — springs from the Jurassic limestone aquifer supply most of the flow, and the river barely responds to rainfall in the normal sense. Flows are remarkably stable through summer; the main limitation is warming in prolonged hot spells. The hatches are modest but reliable: small olives, caddis, and plenty of terrestrial opportunity once the meadows start producing in June. Fish it with very small flies on fine tippet. The trout will inspect rather than grab, and the first cast usually matters more than the fifth. The best beats are informal, local, and worth the effort of finding.

• Limestone