Ben Macdui Southern Cairngorms, 21 August 2010 at 19:12 hours. The huge bulk on the other side of the Lairig Ghru is Ben Macdui, at 4295 feet, it is the second highest mountain in Britain. Taken from the top of Devil's Point. Camera details: EF17-40mm f/4L USM, 0.3 sec at f / 22.