Lough Corrib is the second largest lake in Ireland (after Lough Neagh), 45 km long and 21 km at its widest point with an area of 180 sq. km (17,000 Ha).

It is divided into two distinct regions by the underlying geology. The north-western region of the lake overlies hard acidic rocks like granites and schists; it is by far the deepest part.

The south-eastern arm of the lough is quite shallow and overlies limestone; this is the part which is best for birds.

The best viewing points are accessible from Moycullen (M245335, 7 miles from Galway on the N59 Galway-Clifden Road) in the west, from Angliham marble quarries (M292304) in the east and from Mount Ross (M260424) on the northern side of the 'neck' separating the south-eastern arm from deeper water.

Breeding birds include Tufted Duck, Red-breasted Merganser, Pochard, Gadwall (best seen at Mount Ross in Winter), Shoveler, Common Scoter, Great-crested Grebe, Black-headed and Common Gulls, Common and Arctic Tern, Lapwing, Common Sandpiper, Redshank and Ringed Plover.

In Winter there are large concentrations of Pochard, Tufted Duck and Coot, with large flocks of Lapwing and Golden Plover also present alongside smaller numbers of other duck species, Whooper Swan and Greenland White-fronted Geese.

The area of bog and rough vegetation at Curraghmore often referred to locally as the (Curraghline), just to the north of the Bridge over the River Clare and between the lake and the N84 Galway-Headford Road, is good in Winter for Whooper Swan, Whitefronts and raptors like Peregrine, Merlin and Hen Harrier.