Lough Swilly (Irish: Loch Súilí, meaning "Lake of Shadows" or the "Lake of Eyes") in Ireland is a glacial fjord or sea inlet lying between the western side of the Inishowen Peninsula and the Fanad Peninsula, in County Donegal. Along with Carlingford Lough and Killary Harbour it is one of three glacial fjords in Ireland.
At the northern extremities of the lough are Fanad Head with its famous lighthouse and Dunaff Head. Towns situated on the lough include Buncrana on Inishowen and Rathmullan on the western side. At the southern end of the Lough lies Letterkenny.
The lough is also famous for its wildlife-watching (dolphins, porpoise, sea birds, migratory geese and swans) and diving on the numerous ship wrecks, including the SS Laurentic sunk by a German mine (possible torpedo), which went down with 3,211 ingots of gold of which 3,191 were recovered.
In the south of the lough a number of islands (Burt, Inch, Coney, Big Isle) were poldered and the land reclaimed during the 19th century for agriculture and the Lough Swilly to Derry City Railway embankments. These reclaimed lands are now regarded as one of Ireland's premier wetlands for wildlife conservation and birdwatching, supporting over 4,000 Whooper Swans and thousands of Greenland white front, Barnacle, Greylagg and Brent geese.
Read more about Lough Swilly: History