Coolnasillagh ASSI
This area is of special scientific interest because of its species-rich wet grassland. Species-rich grassland tends to occur only where land management is not intensive, in particular where traditional farming practices have been maintained. As a result, it is not a widespread habitat in Northern Ireland and is often fragmented, consisting of individual fields, parts of fields or banks. Species-rich grasslands, like those found at Coolnasillagh, are a particularly scarce resource in Northern Ireland.
Coolnasillagh is situated within the Coolnasillagh River valley on the lower eastern slopes of Temain Hill, towards the eastern edge of the northern Sperrins block, at an altitude of approximately 200m above sea level. To the north of the site the soils are deep peats, and the remainder of the site is underlain by surface water humic gleys.