For some time there has been doubt over the height of Swirl How. This takes on a greater significance since it may be the high point of the Coniston Fells, in which case it would replace Coniston Old Man in the Top 500 Summit listing. The Ordinance Survey 1:25,000 series has no spot height for Swirl How, although it is included on the 1:50,000 and the height is stated as 802m. Birkett and Wainwright quote 2,630 ft (802 m) as the height, but Richards and the British Mountaineering Council 1:40,000 map quote 2,637 ft (804 m), higher than Coniston Old Man (see below).
Coniston Old Man was normally considered to have a height of 2,634ft or 2,635ft (803m) hence the uncertainty.
Both mountains have been resurveyed recently and it is a dead height. Both Coniston Old Man and Swirl How are included in the Hill Bagging website, the most up to date source for this material at 2,633ft (802.4m). As Coniston Old Man was previously the Marilyn, it continues as the Marilyn.
For the purposes of the Top 500 Summit listing, however, they should be considered as a Siamese Twins or a unique double Top 500 Summit. As the drop between them is only 120m they can only be considered one Top 500 Summit, not two. There is precedent for this in earlier Corbett listings. It was considered that Buidhe Bheinn and Sgurr a’ Bhac Chaolais had the same height and were treated as one Corbett, although Buidhe Bheinn is now considered higher.
The walk over both summits from Coniston is straightforward. Form the village centre follow signs to Coppermines Youth Hostel, 2km up the Church Beck valley. From the Youth Hostel a good path leads to Levers Water, with a big slate sign. On arriving at Levers Water, follow the path along the right hand sign of the tarn and on to Swirl Hawse.
From Swirl Hawse a 600 foot climb up the Prison Band leads to the summit of Swirl How. A grand high level route then goes south passing Levers Hawse and Brim Fell before finally reaching the summit of Coniston Old Man. From the summit a path leads steeply down to Low Water and then to Coniston village past the Miners Bridge