Which is the second highest mountain in the British Isles?

Ben Macdui (Scottish Gaelic: Beinn Mac Duibh) is the second highest mountain in the United Kingdom (in absolute height) after Ben Nevis, and the highest in the Cairngorms National Park. Ben Macdui lies on the southern edge of the Cairn Gorm plateau, on the boundary between Aberdeenshire and Moray.

Before the production of accurate maps of Scotland in the 19th century it was not known for certain that Ben Nevis was the highest point in Britain, and it was often thought that Ben Macdui might be the higher. After Ben Nevis was confirmed as the higher some locals planned to build a cairn on the top of Ben Macdui to make its height greater than Ben Nevis, but these plans did not come to fruition. The summit of the mountain has a direction indicator erected in 1925 by the Cairngorm Club of Aberdeen in memory of a past president, Mr Alexander Copland. The indicator shows the directions of the most important hills that can be seen from the summit in clear weather.