H. P. Lovecraft and his followers placed the mysterious and horror-filled Plateau of Leng in Antarctica, the Dreamlands and (perhaps the same as the Plateau of Tsang) somewhere in the north and west of China. Games inspired by Lovecraft, not least Pathfinder
, have elaborated on the fiction.
Dennis Detwiller's ultra-short "Into the West" in The Way It Went Down
describes a solitary journey and, ultimately, an encounter with some of those who dwell there. The narrator travels west from Lhasa, estimating that he should have reached somewhere near Kashmir, though there are other physical oddities to his travel, such as walking for three weeks without feeling any lack of food and water.
This puts the drear plateau somewhere around the entrance to the Great White Space, or Shangri-La.
I wonder also if it could connect to an extraterrestrial place Leigh Brackett described
, to Hodgson's Borderland, which is in the west of Ireland, apparently, or to the airless Mountains of Death above white and green Yian