The Enfield Blackwater rises north of Prosperous and runs about sixteen miles past Johnstown Bridge and Longwood to the Boyne below Inchamore Bridge. The banks are high in places, but there is plenty of fishable water and a sound stock of wild brown trout from half a pound to a pound and a half — the kind of unfussy river you can spend a whole evening on without meeting another soul. Longwood Angling Association controls the water below Johnstown Bridge and runs it catch-and-release.

• Limestone