The Blue Lagoon.

"The Blue Lagoon" (1980) is a romantic adventure film that tells the story of two young cousins, Emmeline and Richard, stranded on a deserted island in Fiji after a shipwreck. As they grow up in isolation, they develop a deep bond and eventually fall in love, discovering the mysteries of adulthood together. The film showcases the stunning beauty of Fiji's unspoiled landscapes, but it was controversial for its portrayal of teenage sexuality and the casting of a very young Brooke Shields.