The Rhayader boy who supposedly disappeared into thin air is a reminder of an Australian version of the tale which was the inspiration for Picnic at Hanging Rock. The film, of course, starred Llanelli Baptist minister's daughter Rachel Roberts. There's a recent post about Rachel on that interesting Cardiff blog Babylon Wales, read it here.
Anyway here's the local connection: back in the late 1940s, while she was attending Aberystwyth University, Rachel shared a house in Borth with, amongst others, a fellow student, Llanafan born poet, T Harri Jones. Someone really should make a film about that seaside house. Rachel's sexual and chemical excesses were such that the Swinging Sixties really took off in Borth in the 1940's.