Geography of the Isle of Man


The Isle of Man is an island in the Irish Sea, between Great Britain and Ireland in Northern Europe, with a population of almost 85,000. It is a British Crown dependency. It has a small islet, the Calf of Man, to its south. It is located at.

Dimensions

Area:

Land:

Water:


Total:
This makes it:

Coast and territorial sea

The Isle of Man has a coastline of, and a territorial sea extending to a maximum of 12 nm from the coast, or the midpoint between it and other countries. The total territorial sea area is about 4000 km2 or 1500 sq miles, which is about 87% of the total area of the jurisdiction of the Isle of Man. The Isle of Man only holds exclusive fishing rights in the first 3 nm. The territorial sea is managed by the Isle of Man Government Department of Infrastructure.
The Raad ny Foillan long-distance footpath runs around the Manx coast.

Climate

The Isle of Man enjoys a temperate climate, with cool summers and mild winters. Average rainfall is high compared to the majority of the British Isles, due to its location to the western side of Great Britain and sufficient distance from Ireland for moisture to be accumulated by the prevailing south-westerly winds. Average rainfall is highest at Snaefell, where it is around a year. At lower levels, it can fall to around a year.
Temperatures remain fairly cool, with the recorded maximum being at Ronaldsway.

Terrain

The island's terrain is varied. There are two mountainous areas divided by a central valley which runs between Douglas and Peel. The highest point in the Isle of Man, Snaefell, is in the northern area and reaches above sea level. The northern end of the island is a flat plain, consisting of glacial tills and marine sediments. To the south, the island is more hilly, with distinct valleys. There is no land below sea level.

Land use

  • Arable land: 43.86%
  • Permanent crops: 0%
  • Other: 56.14%

Natural hazards and environmental issues

There are few severe natural hazards, the most common being high winds, rough seas and dense fog. In recent years there has been a marked increase in the frequency of high winds, heavy rains, summer droughts and flooding both from heavy rain and from high seas. Snow fall has decreased significantly over the past century while temperatures are increasing year-round with rainfall decreasing.
Air pollution, marine pollution and waste disposal are issues in the Isle of Man.

Protected or recognised sites for nature conservation

In order of importance, international first, non-statutory last. Note that ASSIs and MNRs have equal levels of statutory protection under the Wildlife Act 1990.

UNESCO Biosphere Reserves">Man and the Biosphere Programme">UNESCO Biosphere Reserves

Ramsar sites">Ramsar Convention">Ramsar sites

Designated:
Candidate:

[Important Marine Mammal Areas]

In 2024, the IUCN Marine Mammal Protected Areas Task Force recognised that 17,610km2 of the central Irish Sea as being of global importance for marine mammals, known as the Central Irish Sea Important Marine Mammal Area. This includes about half of Manx marine territorial waters.

[Important Bird Areas]

The UK RSPB and UK JNCC have designated five areas of the Isle of Man which are of global significance to birdlife.

[National Nature Reserve]s

Areas of Special Scientific Importance">SSSI">Areas of Special Scientific Importance

There are 25 ASSIs on the Isle of Man as of November 2022. One additional ASSI has been designated but later rescinded. Dates below refer to year of formal confirmation.

[Marine Nature Reserve]s

The Island's first marine nature reserve was designated in Ramsey Bay in October 2011. In 2018, nine further Marine Nature Reserves were given statutory protection. The ten Marine Nature Reserves around the Isle of Man cover over 10% of the country's territorial waters, in accordance with international requirements.

[Eelgrass] Conservation Zones (Statutory – within MNRs)

Eelgrass Zostera marina is a legally protected species on the Isle of Man. Between 2011 and 2018, four strictly protected Eelgrass Conservation Zones have been designated to protect this important species.
  • Ramsey Bay MNR - Port Lewaigue & Ballure area
  • Baie ny Carrickey MNR - east of Gansey Point
  • Langness MNR - Fort Island Gully
  • Laxey Bay MNR - east of Gob ny Silvas

[Eelgrass] Voluntary Zones (Non-statutory – both in and outside MNRs)

In 2023, three existing statutory Eelgrass Conservation Zones were expanded on a voluntary basis, with a further new site identified.
  • Ramsey Bay - a considerably larger area than the statutory zone
  • Langness - Derbyhaven Bay, northwest of Fort Island, separate from the Fort Island Gully statutory site
  • Laxey Bay - a considerably larger area than the statutory zone
  • Bulgham Bay - discovered in 2021, the only Eelgrass Voluntary Zone outside of an MNR

Areas of Special Protection">Area of Special Protection">Areas of Special Protection

  • Ayres Gravel Pit designated 2001, 41 hectares. In 2019 this became a nature reserve managed by Manx BirdLife.

Bird Sanctuaries">Bird Sanctuary">Bird Sanctuaries

Bird sanctuaries were formerly designated by that name under the Wild Birds Protection Act 1932. This designation was superseded by "Areas of Special Protection for Birds" under the Wildlife Act 1990; however, the following formerly designated Bird Sanctuaries remain protected:
  • Barnell Reservoir 0.02 km2
  • Tynwald National Park and Arboretum
  • Derbyhaven, Langness and Fort Island and foreshores adjoining
  • Renscault and Ballachrink 0.18 km2
  • The Willows 0.01 km2

Registered Heathland">Heath">Registered Heathland

Protected from unlicensed burning or destruction by the Heath Burning Act 2003.
  • Ballacowin
  • Ballaugh Mountain
  • Beary Mountain
  • Bienn y Phott
  • Bradda
  • Calf of Man
  • Carraghyn
  • Central Hills ASSI
  • Creg ny Baa
  • Cringle Great Park
  • Cronk ny Arrey Laa
  • Cross Vein, Watertrough Park and Glen Rushen
  • Dalby Mountain
  • Glen Auldyn
  • Greeba Mountain
  • Injebreck
  • Lanagore and Eary Cushlin
  • Maughold Mountain
  • Michael Hills
  • Mull Hill
  • Mullagh Ouyr
  • North Barrule
  • Peel Hill
  • Slieau Lhean
  • Slieau Lhost and Slieau Ree
  • Slieau Managh
  • Slieau Whallian
  • Snaefell
  • South Barrule
  • Surby
  • Chasms and Spanish Head
  • The Rheast
  • Windy Common

Nature Reserves and Wildlife Sites">Nature Reserve">Nature Reserves and Wildlife Sites

Manx Wildlife Trust Reserves

Manx Wildlife Trust was founded on 6 March 1973 and is the Isle of Man’s leading nature conservation charity.
As of May 2025, MWT manages 32 nature reserves, including the Calf of Man which is managed with and on behalf of Manx National Trust. These reserves total, or around 2% of the Isle of Man and include:
NameAcquiredAreaNotes
Aust2016
Ballachrink2011Part of the Renscault & Ballachrink Bird Sanctuary
Ballachurry2016
Ballamooar Meadow1994
Barnell Reservoir1974 & 1984Part of the Ballamoar Bird Sanctuary
Billown2023Includes Rosehill Quarry ASSI
Breagle Glen and Cronk Aash1988, 1991 & 2010
Calf of ManN/AOwned by Manx National Trust, co-managed in partnership with Manx Wildlife Trust since 2006. Candidate Ramsar site
Close e Quayle1994 & 2003
Close Sartfield1987Part of the Ballaugh Curraghs ASSI and Ramsar Site
Close Umpson1995Part of the Ballaugh Curraghs ASSI and Ramsar Site
Cooildarry1976 & 1979
Creg y Cowin2023
Cronk y Bing1989An Area of Special Scientific Interest
Curragh Feeagh1986
Curragh Kiondroghad 1988 & 1990
Dalby Mountain1995 & 2024Candidate Ramsar site, Part of the "Isle of Man Hills" Important Bird & Biodiversity Area
Dalby Mountain Fields1995Part of the "Isle of Man Hills" Important Bird & Biodiversity Area
Dobbie's Meadow2013
Earystane1998
Fell's Field1998
Glen Auldyn2025Part of the "Isle of Man Hills" Important Bird & Biodiversity Area
Glen Dhoo1995
Glion Darragh2024
Goshen1995, 1998, 2008 & 2023Part of Ballaugh Curraghs ASSI and Ramsar Site
Hairpin Woodland Park2019, 2022, 2024 & 2024
Lough Cranstal1989 & 2022Candidate Ramsar site
Lough Gat e Whing2016
Miss Guyler's Meadow1989
Moaney & Crawyn's Meadows1995Part of the Ballaugh Curraghs ASSI and Ramsar Site
Mullen e Cloie2008
The Keyllagh2024
TotalThis represents approximately 2% of the Isle of Man's land area

Designated Wildlife Sites

The Isle of Man has 92 non-statutory 'Wildlife Sites' covering in addition to the 10.4 km of coastline. As of 30 January 2009 this total was 45 wildlife sites, covering about 195 ha of land and an additional of inter-tidal coast. Wildlife Sites are not recognised in law, but are recognised in terms of Government policy, including planning and zonation and agricultural policy. Wildlife Sites are shown on the MANNGIS Island Environment map.

Other Nature Reserves

  • Ballalough Reedbeds: managed by Castletown Commissioners
  • Ballanette and Clay Head Brooghs: nature reserve, private but open to the public
  • Snaefell Valley: nature reserve, private but open to the public
  • Manx BirdLife Ayres National Reserve

Manx National Trust">Manx National Heritage">Manx National Trust Landholdings

The following properties are under the protection of Manx National Heritage. The Manx National Trust owns properties in 15 of the 17 Manx parishes.
  • Andreas: Ballakeil, Kerroogarroo
  • Arbory: Ballayack, building at the Friary
  • Ballaugh: Ballaugh Curragh
  • Braddan: Marine Drive, Braddan Pinfold
  • Bride: The Ayres: Ballakesh, Ballawhannel
  • Lezayre: Vollan Fort, The Grove, Killabrega, Sulby Glen
  • Lonan: Ballacowle, Bulgham, Laxey Wheel, Gretch Veg, King Orry's Grave, Laxey Head, Cronk y Chule
  • Malew: Silverdale Glen, Hango Hill, St Michael's Isle, Rushen Abbey, Castle Rushen
  • Marown: Upper Ballaharry, The Braid
  • Maughold: Maughold Head, Maughold Brooghs, Gob ny Rona, Maughold Green, Baldromma, Port Lewaigue, Ballaterson, Dhoon, Port e Vullen
  • Onchan: Scollag Road
  • Patrick: Eary Cushily, Ennin Moar, Creggan Mooar, Peel Castle, Niarbyl, Doarlish Mooar, Knockuskey
  • Rushen: Cregneash, Chasms, Kitterland, Shenvalley, Meayll Hill, Sugarloaf, Calf of Man, Church Farm, Glen Chass, Rheast Mooar, Fistard, The Sound
  • Santon: The Broogh Fort

Geology

The majority of the island is formed from highly faulted and folded sedimentary rocks of the Ordovician period. There is a belt of younger Silurian rocks along the west coast between Niarbyl and Peel, and a small area of Devonian sandstones around Peel. A band of Carboniferous period rocks underlies part of the northern plain, but is nowhere seen at the surface; however similar age rocks do outcrop in the south between Castletown, Silverdale and Port St Mary. Permo- Triassic age rocks are known to lie beneath the Point of Ayre but, as with the rest of the northern plain, these rocks are concealed by substantial thicknesses of superficial deposits.
The island has significant deposits of copper, lead and silver, zinc, iron, and plumbago. There are also quarries of black marble, limestone flags, clay schist, and granite. These are all modern, and there was no noticeable exploitation of metals or minerals before the modern era.

Demographics

The island has a census-estimated population of 84,497 according to the most recent 2011 census: up from 79,805 in 2006 and 76,315 in 2001.
The island's largest town and administrative centre is Douglas, whose population is 23,000 – over a quarter of the population of the island. Neighbouring Onchan, Ramsey in the north, Peel in the west and the three southern ports of Castletown, Port Erin and Port St Mary are the island's other main settlements. Almost all its population lives on or very near the coast.