Eventually inevitable Deborah Kerr completism. She's very young here, playing a Sister who would be superior in an Anglican order of working nuns, sent from Kolkata to her own semi-private Kafiristan to enlighten the natives. We're shown in flashback that she was abandoned by a brainless Irishman set on making money in America. This appears to have inoculated her against the charms of males, incarnated in the valley by David Farrar who looked like the 1980s matinee idol Richard Chamberlain (The Thorn Birds (1983)) with tonsils to match. Sabu (The Thief of Bagdad (1940)) as The Young General may also have been expected to have interested the Sisters but he of course goes for the lowborn, apparently-mute Jean Simmons (in brownface and cheap jewellery).
All the nuns looked the same to me (all wearing a fair bit of makeup) which made it a relief when fruity Kathleen Byron (Sister Ruth) got out of her habit and did the Brides of Christ (1991) thing. All are histrionic and overwrought to some extent which is exacerbated by the film barely showing their quotidian existence. At times it dons the camp motifs of classic horror (obtrusive music, insufficiently-motivated histrionic cackling laughter, shadows, ...) to bewildering effect. I didn't really grasp what the point of it all was.
The Technicolor cinematography is sometimes amazing, especially given that it was shot on sets in England and Ireland; it got Jack Cardiff an Oscar. Written and directed by Michael Powell Emeric Pressburger. Based on a novel by Rumer Godden.
Someone at the New York Times. IMDB trivia: indeed the valley is populated by people from all over Asia.