A still from Iain Miller's YouTube video of the Cnoc na Mara climb

If you don’t have a head for heights, you may want to skip this vertiginous video from climber Iain Miller.

Miller has compiled a guide to climber’s guide to the sea stacks in the remote North-West of Ireland.

And this YouTube film shows a cragrat’s view of him successfully ascending Cnoc na Mara, a 100m-high sea stack near An Port, County Donegal.

He says: “It is safe to say this stack represents all that is great about adventure climbing.

“Its impressive soaring 150m long landward arête provides one of the most rewarding and adventurous rock climbs in Ireland. It is easily an equal to the mighty Old Man of Hoy off the Orkney Islands in the North of Scotland.”

Cnoc na Mara is accessible by a 2km sea paddle.

Iain Miller, of outdoor activities provider Unique Ascents, is an experienced mountaineer with over 25 years’ experience as a mountaineer and rock climber combined with 10 years’ experience of mountain instruction. He has made more than 1,000 first ascents of sea stacks, sea cliffs and rock faces in both Ireland and Scotland.

He says of his free downloadable guide to the climbs: “For the past five years we have been exploring and climbing the previously unclimbed sea stacks found around the coastline of Donegal.

“What this collection of sea stack climbs provides is a lifetime’s worth of outstanding adventure climbing is some of the most beautiful, remote and atmospheric locations in Ireland.

“Many of these stacks lie in very inaccessible locations at the bases of huge sea cliffs far from any easy access and they require a comprehensive understanding of the sea to ensure a safe ascent of these superb climbs.”

The guide also contains conventional climbing locations in suitably atmospheric locations around the coast and islands of Western Donegal as suitable alternative climbing venues if the seas are too rough for a safe access to the stacks.

The guide can be downloaded from the Unique Ascents website.