Nicholas Roerich (1874-1947) was a Russian painter, occultist (theosophist -- of which he produced his own variety, Agni Yoga --, Orientalist) and philosopher. His expedition to Central Asia -- in 1925-9 -- produced several series of haunting and disturbing Asian pictures, which catch something of the feel of alien realms of ice and piercing cold, strange mountains dotted with monasteries and fortresses of no familiar nor wholesome architecture.
The Thibetan and Himalayan series received, and merited, the highest praise from H.P.L.: “Better than the surrealists . . . is good old Nick Roerich, whose joint at Riverside Drive and 103rd Street is one of my shrines in the pest zone. There is something in his handling of perspective and atmosphere which to me suggests other dimensions and alien orders of being—or at least, the gateways leading to such. Those fantastic carven stones in lonely upland deserts—those ominous, almost sentient, lines of jagged pinnacles—and above all, those curious cubical edifices clinging to precipitous slopes and edging upward to forbidden needle-like peaks!''
A reasonably close study of Roerich's paintings produces the effect that Lovecraft described -- there is something in the pitch and shape and shadows of his mountains, in the slightly but perceptibly angled dream-perspective, in the rising of range after range of strange mountains at vertiginous angles, pitching and reeling, rising as no mountain I have seen rises, into the pallid and empty skies (is it this quality, the dizziness of the great hights, that partly creates the feeling of no wholesome nor earthly geometry and dimensions?.
Sometimes they seem to blur and haze, or to rise sickeningly high from cold abysses of cloud and mist. Occassionally one sees a curious graven quality to a peak, or else an arrangement of rock and shadow that half-suggests a leering face -- never so plainly so that one can be sure, which adds to the horror -- , but often the ''sentience'' which Lovecraft remarks upon seems to come from the sheer masses of white peak and blue abyss and the strange shadows, one can almost hear the thin piping of the wind.
The peaks are at times flat or strangely angled, a quasi-geometric effect which is a possible inspiration for the cities of the Elder Ones.
Roerich's citadels and monasteries seem to be masses of rectangular prisms, great slabs of Cyclopean dressed and polished stone without joint or mortar and relieved very little, if not actually worsened, by strange and alien finials.
There is a strangely graven, steatitic, greenish stone in his ''Path to Kailas'' that suggests to me, rather indescribably -- I think it is in its shade -- the strange soapstone of the Elder Ones.