Sperrin Mountains

The Sperrin Mountains, stretching along the border of counties Tyrone and Derry, can best be described as wild, untouched and beautiful. Spanning 40 miles, the Sperrins mountain range is the largest in Ireland. Walkers can expect undulating hills covered in heather, quiet valleys, boggy uplands and a land teeming with wildlife. There are 10 summits above 500m with the highest of the range, Sawel Mountain, peaking at 678m (2,224ft).

Stone Circles

Over 90 sets of stone circles have been found in the Sperrins, the best known being Beaghmore Stone Circles in the south east of the range. Despite being relatively small in stature, the alignments of the Beaghmore Stone Circles accurately correlate to movements of sun, moon and stars.

Geology

The Sperrin Mountains are made up of metamorphic rocks which were deposited between 700 and 600 million years ago. The original rocks, mostly sandstones, mudstones and limestones, were changed by enormous heat and pressure caused by mountain building processes.

The last ice age has had a great impact on the Sperrins and the great ice sheets that covered the north of Ireland were probably at their thickest over the Sperrins. This area retained its ice sheet for a time after the retreat of the ice began – this has caused many of the present features of the Owenkillew Valley and the Glenelly Valley such as eskers. All of these eskers are of significant value and are exploited for materials for the construction industry.

As the ice retreated in the area, valleys were temporarily obstructed by ice sheets. This led to valleys filling with water which escaped into adjoining lowland. This often resulted in erosional features called glacial overflow channels. Found in many mountainous areas throughout Ireland, some of the best examples are in the Sperrins. Barnes Gap and Gortin Glen are two such overflow channels.