This is a comfortable and very pleasant hill walk through ancient woodland, with contrasting surroundings and surprisingly long views from the higher parts. Watch out for fallow deer and red squirrels along the way, but don’t expect to see a castle. What is known locally as Glinsk Castle is really a heap of stones on a wooded hilltop marking the site of an old castle.

Leave the car park and follow the forestry track into the coniferous wood. The track, which is lined with brambles that promise autumn feeds of blackberries, continues into a mixed woodland of old oaks, beech trees, and surprisingly a few surviving elms, the remains of a woodland planted in the late 19th century by the Bernard family of Castle Bernard, owners of all the lands about here. Castle Bernard is now Kinnitty Castle Hotel. The woods were taken over in the 1920s by the State, and the old trees were underplanted with larch and spruce.

For a while, except for occasional birdsong, there is a cathedral-like stillness in the forest of tall, column-like conifers, before the route comes into the open and ascends through a gateway in a deer fence into an area where the older forest has been cleared. From time to time along the track the trunks of great and ancient trees lie where they fell, providing new habitats for flora and fauna. There are signs that there has been a cull of rhododendrons along here also, but it is an extraordinarily resilient shrub, and between the dead, felled branches, bright green shoots are already appearing.

As the route gently ascends, long views of the plains to the north-west open up. The route zig-zags uphill and then turns sharply onto a path that meanders under towering beeches, passing the ancient remains of stone walls, thickly clothed in moss, harking back to a time long before the beech trees were planted, when there were open fields here. The route emerges from the dark woods onto a forestry track with long views opening up again to the north. A fine, new oak, larch and willow plantation is passed, protected from the local deer by tall wire fences.

The forestry road winds gently uphill, and as it climbs a long straight section, the broad expanse of landscape opening up to the west behind includes a glimpse of glittering Lough Derg, taking Ireland’s longest river, the Shannon, southwards towards Limerick. A gravel path then leads off the forestry track and takes the route past its highest point of 325m, to reach what is known as Glinsk Castle, represented by two small heaps of stone, like a ruined gateway, in a clearing. It is said that the original castle here was built in timber as a lookout early in the Norman invasion, but no traces of it remain today.

Our descent now begins into the deep and emerald green Glenregan valley, patterned with a patchwork of fields, at the bottom of which the Camcor River flows on its journey to the Little Brosna and eventually, the Shannon.

On the far side of the valley the ground rises steeply to three summits of the Slieve Bloom Mountains, Knocknaman, Forelacka and Stillbrook Hill, and the horizon beyond is lined with wind turbines.

It is a most pleasant and gentle descent, down a path between the silvered stumps of harvested trees standing sentinel over newly planted spruces. Eventually the route enters the old oakwood again, and descends back to the carpark and the end of the loop.