Lost Horizon by James Hilton (1933) — see its film and TV adaptations.
Following a plane crash, Conway, a British consul; his deputy; a missionary; and an American financier find themselves in the enigmatic snow-capped mountains of uncharted Tibet. Here they discover a seemingly perfect hidden community where they are welcomed with gracious hospitality. Intrigued by its mystery, the travellers set about discovering the secret hidden at the shimmering heart of Shangri-La.
