In good weather the southwest of Ireland is sublime. When the mist is down, however, visitors wonder at how local people can remain sane in such a grey world. It’s one of the latter days when I arrive at Drimoleague, in west Cork, the first section of St Finbarr’s pilgrim trail to Keakill. My starting point is known as the Top of the Rock, from which a well-constructed trail disappears into a mist-laden valley. I follow downhill to pretty Ahanafunction Bridge, where the clag lifts briefly to allow tantalising glimpses of the green highlands above Castledonovan. A short distance on a quiet road is followed by a saunter along the banks of the River Ilen.

The sun emerges to dapple the hurrying waters of some cascades, before emerging at Castledonovan and the imposing stature of the ruined Donovan clan fortress and rambling uphill through countryside that escaped the Celtic Tiger’s calling card.

After passing a huge boulder, rising like the head of a subterranean monster, the path turns imperceptibly uphill to an amazing lake atop the surrounding bogs. Immediately I wonder where the water came from and how it remains in place. Mulling over this enigma, I reach a high point and a sign for the house of George the Sky. This appellation refers to George Mahoney, a local hill farmer, who resided in an elevated abode nearby. Without time to investigate the dwelling, I descend instead towards Coomanore Lough, beguilingly attractive, with its tranquil waters that urge you to linger.

Pushing on around Coomanore to the cairned summit of Mullaghmesha (494m), my attention is captured by the great island-strewn expanse of Bantry Bay gleaming below. Descent is along a broad ridge and then through woodland to reach a paved road. Here a further steep decline leads to a stile going left and a traverse of rough mountainside to reach the road bisecting Meelagh Valley. Tagging the walking arrows into a plantation, I come upon an isolated link to the past in the form of an ancient burial tomb. Pausing, I wonder who lies here and why were they of such stature that prehistoric persons unknown felt compelled to sweat this great capstone into place .

Next it’s a rapid transition from ancient to modern with a steel bridge across the River Meelagh. Then another abrupt change of scenery finds me bisecting a young broad-leaved plantation to reach a busy public road, where the ensuing 4km on tarmac prove the vexatious lowlight of the day.

Later, on a minor road, things improve, with sweeping vistas over the Cork coastline towards the mythical Beara Hills, flowing into each other beyond. Arriving at Keakill village, I tarry at Burke’s shop to enjoy a welcome infusion of caffeine. Here, while awaiting a taxi back to Drimoleague, I conclude that if the mythical hidden Ireland exists, I have surely crossed its heartland.

John G O’Dwyer’s guidebook to the ancient pilgrim paths of Ireland will be published by the Collins Press in April