From the website:
One could say that the Alberta Rocky Mountain tradition of having tea on a mountain top began at Lake Agnes. Since 1905, the Lake Agnes Tea House has been serving, with pride, fine loose leaf teas to visitors from around the world.
Lake Agnes was named for original First Lady of Canada - Lady Agnes MacDonald, the wife of Canada’s first Prime Minister. In 1886, Lady MacDonald visited Lake Agnes and was delighted by the beauty of this idyllic lake and the hanging valley it sits in.
The Lake Agnes Tea House was originally built in 1901 by the Canadian Pacific Railway, as a refuge for hikers, and started serving tea in 1905. The log building was replaced in 1981 but still features the original windows, tables and chairs.