Physical Geography & Climate , County Leitrim The region encompasses the entire northwest coast of Ireland along the
Atlantic Ocean. Two of
Ireland's longest rivers, the
Shannon and the
Erne, have their source in the region. The Shannon rises from the famed
Shannon Pot in County Cavan and the Erne rises from Slieve Glah, also in County Cavan. The two rivers have been connected to form one of the world's longest waterways - the
Shannon–Erne Waterway. Cavan and Monaghan in the east of the region are characterized by a drumlin landscape, with hundreds of loughs interspersed between.
Lough Allen in Leitrim is the region's largest lake, at 35 km2. The west of the region, from
Tullyhaw, County Cavan, to the Atlantic coast is largely rocky and mountainous, with dramatic coastal cliff landscapes as well as pure sand beaches seen in counties Sligo, Donegal and Leitrim. Leitrim has the smallest coastline of any county, at just 5 km in length, while Donegal has the longest, at 1,134 km (just over 706 miles). According to the 2017 National Forestry Inventory, there is a total of of forest and woodland cover in the Border Region, equating to 11.3% of the region's land area. This is in keeping with the national average forest cover of 11%. The region traditionally had a very low cover forest and planting schemes were undertaken by the Department of Agriculture or
state-sponsored bodies such as
Coillte. Forest cover in the region has increased rapidly in recent years, primarily driven by the emergence of
Privately owned forests. This is especially evident in County Leitrim, which is now Ireland's most forested county at 18.9% forest cover, having overtaken
County Wicklow, and up from just 12.9% in 2006. Unlike County Donegal, where two-thirds of the county's forests are state-owned, over 50% of County Leitrim's forests are under private ownership. Under
Köppen climate classification, the region experiences a maritime
temperate oceanic climate with cold winters, mild humid summers, and a lack of temperature extremes.
Met Éireann has several monitoring stations across the region which record climate data. Summer daytime temperatures range between , with temperatures rarely going beyond . While the region generally experiences mild winters, upland areas, particularly in Donegal, typically receive snowfall each year. Humidity is high year round and rainfall is evenly distributed throughout the year, with annual precipitation ranging from ~1,250 mm (
Markree Castle, Sligo) to ~1,000 mm (
Ballyhaise, Cavan).
Geology , County Sligo There are many large mountain ranges and high sea cliffs in the region, such as the
Derryveagh Mountains,
Slieve League, the
Cuilcagh Mountains and
Ben Bulben. The region is generally underlain by
Ordovician and
Silurian Shales and Greywackes, laid down 417-495 million years ago. These are found in eastern Cavan and Monaghan. The bedrock of western Cavan, Leitrim and Sligo is composed mostly of
Carboniferous limestones that were laid roughly 355 million years ago. However, a 1.5 billion year old narrow strip of metamorphosed gneisses extend across Sligo near the
Ox Mountains.
County Donegal in
Ulster has one of the most complex geologies in Ireland. Much of the county is underlain by
Precambrian gneiss, schist and quartzite, laid down during the Grenvillian Orogeny 700 million years ago. The Border Region's highest point,
Errigal, at , is composed of Precambrian quartzite. Ireland's oldest rocks, laid down 1.78 billion years ago, are found on the island of
Inishtrahull. Inishtrahull is Ireland's most northerly island, located approximately 10 km north of
Malin Head, mainland Ireland's most northerly point.
Lough Swilly in Donegal is one of Ireland's three fjords. Owing to its scenic and rugged landscape, Donegal was named
National Geographic's "
Coolest place on the Planet" in 2017.
Gallery File:SlieveLeague ToneMapped.jpg|
Slieve League, County Donegal File:Countyleitrimcows.jpg|
Dromahair, County Leitrim File:Mullaghmore, Co Sligo.jpg|
Mullaghmore, County Sligo File:Loughter.JPG|
Killykeen, County Cavan Lough Muckno Co.Monaghan Eire. - geograph.org.uk - 507755.jpg|
Lough Muckno, County Monaghan ==Transport==