Nikolai Roerich (1874-1947) was a Russian painter who traveled through Tibet in the 1920's painting the Himalayan mountain. His works can be seen at the Roerich Musem in New York City where Lovecraft saw them.
Professor Dyer, the author of "At the Mountains of Madness writes of the great barren peaks of Antarctica that, "Something about the scene reminded me of the strange and disturbing Asian paintings of Nicholas Roerich, and of the still stranger and more disturbing descriptions of the evilly fabled plateau of Leng which occur in the dreaded Necronomicon of the mad Arab Abdul Alhazred."
From a radio message from Professor Lake: "Odd formations on slopes of highest mountains. Great low square blocks with exactly vertical sides, and rectangular lines of low, vertical ramparts, like the old Asian castles clinging to steep mountains in Roerich's paintings. Flew close to some, and Carroll thought they were formed of smaller pieces, but that is probably weathering. Most edges crumbled and rounded off as if exposed to storms and climate for millions of years."
An exhibit of some of Nicholas Roerich's works can be found in the Miskatonic University Museum.
("At the Mountains of Madness")