Baosbheinn has one noteworthy geological feature: it being the site of the largest and most impressive protalus rampart in Great Britain. The rampart is situated at the NW end of the ridge below the crags of Creag an Fithich at a height of around . It formed in post-glacial times when a massive rockslide or series of rockslides involving failure of approximately 200,000 m³ of rock over-rode a former snowbed and accumulated as a boulder ridge. The north west end of Baosbheinn where the protalus rampart is situated has been designated a Site of Special Scientific Interest over an area of 39,000,000 m².