Slieve Gallion

Slieve Gallion

Overview

Slieve Gallion is a 526.6 m mountain at the eastern edge of the Sperrins in County Londonderry, Northern Ireland. Its main summit is the trig point at H798878, southwest of the separate, lower northeast top with its communications mast. An ascent through Iniscarn Forest continues across open upland to the main summit, with views towards Lough Neagh.

Main summit and northeast top

The main summit is the trig point at H798878, 526.6 m above sea level. The communications mast and visitor cairn are on the separate northeast top at H813896, which is 493.6 m high. Reaching the mast does not complete an ascent of the main summit.

Route: Iniscarn Forest to the main summit and back

Start and finish at the Iniscarn Forest entrance on Iniscarn Road near Brackagh Road. Follow the climbing forest road, take the left branch by the old house and continue through the upper forest. Cross the stile onto moorland and climb to the northeast mast top. Continue southwest across the upland saddle to the main trig-point summit at H798878. Retrace the same route over the northeast top and down through the forest to the start. Allow 3.5–5 hours for this 12.4 km return outing, with 513 m of ascent. Expect steep, uneven ground and exposed moorland; follow forestry notices and keep dogs on a lead.

Terrain and navigation

Gravel forest roads and narrower tracks climb through Iniscarn Forest to a stile and open moorland. Beyond the northeast top, the route crosses uneven, peat-covered upland towards the main summit. Open upland and peat-covered ground separate the northeast top from the main summit; mist can obscure the route. Carry a map and compass and know how to use them.

Parking and access

Parking is permitted at the Iniscarn Forest entrance on Iniscarn Road, near Brackagh Road. Keep the gates and forestry-vehicle access clear. Follow any operational signs or temporary restrictions. Iniscarn is a working forest. Obey forestry safety signs, closures and diversions, and keep vehicle access clear. The uplands include privately owned grazing land. Keep dogs on a lead, respect livestock and use gates and stiles carefully.

Public transport and facilities

Check Translink’s journey planner for buses to Desertmartin or Magherafelt and confirm the outward and last return services for your walking date. Arrange the onward connection to the Iniscarn Forest entrance. There are no toilets at the Iniscarn Forest trailhead. Use facilities in the surrounding towns before setting out and carry food and water for the full return walk.

Views and wildlife

In clear weather, the upper slopes and summits overlook Lough Neagh and the surrounding countryside. The northeast top also gives views towards the Antrim plateau and north towards Donegal. Clear visibility offers the best views over Lough Neagh and the surrounding countryside. Buzzards may be seen displaying above Iniscarn’s mature hardwoods in spring.

Geology and peat

Slieve Gallion has complex igneous geology, including granodiorite and rhyolitic porphyry exposed on its southeastern side. Its volcanic rocks are associated with the Tyrone Volcanic Group. Peat in the saddle between the two tops preserves a vegetation record extending back about 10,000 years, while later blanket peat covers much of the upland.

Name and history

Sliabh gCallann is interpreted as “mountain of the heights”. Local stories also associate the mountain with the legendary Callan. Slieve Gallion features in the traditional song Slieve Gallion’s Braes. Local folklore associates the cairn on the northeast top with Callan, a legendary descendant of Colla Uais. The mountain’s peat deposits also preserve a much longer record of environmental change.

Nearby summit

The separate Slieve Gallion NE Top is 493.6 m high at H813896 and is visited on the Iniscarn approach to the main summit.

Conditions

Heavy rain can soften peat and make paths muddy. Wind, low cloud and short winter days increase the demands of the open upland section; frost or snow can make steep ground slippery. Check the forecast and allow time to return through the forest in daylight.