County Donegal shares border with County Leitrim
Geography and subdivisions
Located in the northwest corner of Ireland, Donegal is the island's northernmost county. In terms of size and area, it is the largest county in Ulster and the fourth-largest county in all of Ireland. Uniquely, County Donegal shares a small border with only one other county in the Republic of Ireland – County Leitrim. The vast majority of its land border (93%) is shared with three counties of Northern Ireland: County Tyrone, County Londonderry and County Fermanagh. This geographic isolation from the rest of the Republic has led to Donegal people maintaining a distinct cultural identity and has been used to market the county with the slogan "Up here it's different". While Lifford is the county town, Letterkenny is by far the largest town in the county with a population of just under 20,000. Letterkenny and the nearby city of Derry form the main economic axis in the northwest of Ireland. Indeed, what became the City of Derry was officially part of County Donegal up until 1610.
It is part of the Northern and Western Region (a NUTS 2 European statistical Region), within which it is part of the Border strategic planning area.Physical geography
The county is the most mountainous in Ulster consisting chiefly of two ranges of low mountains; the Derryveagh Mountains in the north and the Blue Stack Mountains in the south, with Errigal at 751 m (2,464 ft) the highest peak, making it the 11th-highest county top in Ireland. It has a deeply indented coastline forming natural sea loughs, of which Lough Swilly and Lough Foyle are the most notable. Donegal boasts the longest mainland coastline of any county in Ireland, and has either the longest or third longest total coastline (including islands), depending on measurement. Length estimates of the Donegal coastline range from less than 1,000 km (621 mi) to 1,235 km (767 mi). The official figure used by Donegal County Council is 1,134 km (705 mi). The Slieve League cliffs are among the highest sea cliffs in Europe, while Malin Head is the most northerly point on the island of Ireland.
Two permanently inhabited islands, Arranmore and Tory Island, lie off the coast, along with a large number of islands with only transient inhabitants. The 129 km long River Erne, Ireland's ninth-longest river, enters Donegal Bay near the town of Ballyshannon. The River Erne, along with other Donegal waterways, has been dammed to produce hydroelectric power. A canal linking the Erne to the River Shannon was constructed between 1846 and 1860, creating Ireland's longest navigable waterway. The project was plagued with setbacks and closed in 1870, just ten years after its completion. A joint effort between the Irish and Northern Irish governments restored the canal in the late 20th century, and the Shannon–Erne Waterway reopened in 1994.Historically, the eastern boundary of the kingdom of Tír Chonaill was demarcated by the River Foyle. However, in the 17th century, an area of land west of the Foyle was given over to the newly established city of Derry; although the Foyle still demarcates a large section of Donegal's eastern border. To the south, the Drowes River forms a 9  km (6 miles) long natural boundary with County Leitrim.
Donegal has a population density of 34.2 people per square kilometre, the lowest in Ulster and the fifth lowest in Ireland. The county has an expansive network of wildlife and conservation zones, which includes 46 European Union designated Special Areas of Conservation (SACs) and 26 Special Protection Areas (SPAs), as well as 14 Natural Heritage Areas (NHAs), 74 proposed Natural Heritage Areas, 145 Irish Geological Heritage Areas (IGHs) and Ireland's second largest national park, Glenveagh, which extends to over 42,000 acres (170 km2) in northwestern Donegal.Owing to its scenic landscape and "world-class wilderness", Donegal was named National Geographic's "Coolest place on the Planet" in 2017.The forested area in the county extends to 55,534 ha (137,228 acres), the 4th highest total forest cover in Ireland. Historic deforestation left Donegal devoid of forest cover by 1900. Much of the county's forests are commercial timber plantations which were initially established in the 1930s as a way to create rural employment in areas with poor agricultural land and high rates of emigration. The county contains extensive tracts of blanket bog which are concentrated in western and upland regions. Blanket bog covers an area of 148,656 ha (367,337 acres), or roughly 30 percent of the entire county.
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