Sapper's Bothy
A ruined stone ‘bothy’ just east of the summit of Ben Macdui built around 1847 by (or for the use of) the survey team from the Ordnance Survey who surveyed the Cairn Gorm / Ben Macdui plateau. This survey settled the argument around whether Ben Macdui or Ben Nevis was the highest mountain in Britain.
In Watson (1975) the author gives its map reference as 991988.
Read more about this topic: Places, Place Names, And Structures On Mar Lodge Estate