A large, shallow sea inlet and estuary of the River Foyle, with extensive mudflats, especially along its eastern shore. The site lies immediately north of Derry city, on the north County Donegal/Derry coast. It is a cross-border IBA, with most of the site falling within County Derry in Northern Ireland (UK site 278). The stated area of 21,803 ha refers to the whole site (on both sides of the border). Most of the birds occur on the Derry side, and the Donegal side is used only occasionally by some species. The lower numbers on the Donegal side mean that the criteria for the Republic of Ireland site can only be met when taking a transboundary view, but the site should remain as an IBA for site management and integrity purposes. The counts given in the Species at site section are from the Northern Ireland side and the data from the Republic of Ireland side is included in the Ornithological information section (below).
This site is of international importance for wintering waterfowl. Most of the birds use the Northern Ireland section of the site, but notable concentrations of Branta bernicla (305, 1.2% of flyway), Mergus serrator (53, 1.5% of national population), Podiceps cristatus (82, 1.5% of national population), Larus ridibundus (281) and Larus canus (236) use the Republic of Ireland (Donegal) side. Counts shown are for individuals from winter 07/08.