The Aire Valley is a long and thin river catchment starting on the upland moors of the Yorkshire Dales, running through the heart of Leeds and out to the Humber estuary across what was once lowland fen and marsh though now largely converted to intensive arable production. The River Aire flows for 148 kilometres from its source in the Yorkshire Dales near Malham to its confluence with the River Ouse at Airmyn (‘myn’ is an old English word for ‘river mouth’) near Goole.
The top of the catchment sits in the Yorkshire Dales National Park and is characterised by karst limestone landscapes, including the iconic Malham Cove and its limestone pavements. From Skipton, the valley was heavily industrialised and is increasingly urban eventually flowing into Leeds. From Castleford, the river runs through a very rural area dominated by intensive arable agriculture.
According to Wikipedia:
The Aire rises at Malham Tarn then flows underground to Aire Head, near Malham, in North Yorkshire, and then flows through Gargrave and Skipton. After Cononley, the river enters West Yorkshire where it passes through the former industrial areas of Keighley, Bingley, Saltaire and Shipley. It then passes through Leeds and on to the villages of Swillington and Woodlesford. At Castleford is the confluence of the Aire and Calder; just downstream of the confluence was the ford where the ancient British road, used by the Romans, crossed on its way north to York. The river re-enters North Yorkshire near Knottingley and in its lower reaches forms part of the boundary between North Yorkshire and the East Riding of Yorkshire.
The catchment includes fine scenery and sites of very high environmental quality including 22 Sites of Special Scientific Interest (SSSI), four Special Areas of Conservation (SACs) and two Special Protection Areas (SPAs). There are 219 Scheduled Ancient Monuments and one World Heritage Site, at Saltaire, in the catchment.