The River Suir is a premier limestone river in Ireland's southeast, flowing approximately 185 kilometers from its source in the Devil's Bit Mountains of County Tipperary. It courses south and then east through towns like Cahir, Clonmel, and Carrick-on-Suir before reaching its tidal estuary near Waterford City. The river's defining characteristic is its alkaline, nutrient-rich water, which drives exceptional aquatic productivity and supports a world-class fishery. Unlike many rivers, the Suir is challenging to divide into distinct ecological zones; from Templemore down to Carrick-on-Suir, it largely consists of a continuous series of shallow and deep glides, occasionally interrupted by shallow riffles, with the channel simply widening as it flows downstream while maintaining excellent trout habitat. The river is tidal upstream to a point above Carrick-on-Suir. Access often involves crossing farmland, and anglers must always respect private property, leaving gates as found and avoiding blocking access.