Now within the Balmoral estate, Glas Allt is a stream running down from the plateau of the White Mounth, near Lochnagar. Passing over the considerable Falls of Glas Allt, the burn runs into a point near the head of Loch Muick through a relatively flat delta amidst otherwise hilly and rocky land. Here a single-storey stalker's cottage was built in 1851 for Charles Duncan, employed as an estate gillie, and his wife. This cottage seems to have had a room for royal parties and it predates the lodge of 1868. Adam Watson considers that Glas-allt-Shiel has undoubtedly one of the most spectacular situations of any lodge in the Highlands.