Franco’s (loose) adaptation of Robert Louis Stevenson’s Treasure Island, a story about a guy who looks for treasure on an island and gets seduced by the sirens, in other words a fun adventure/sleaze romp with Uncle Jess (Sinfonia Erotica) An obscure film, this was apparently produced in 1981 under the title La isla de las virgenes, and was later released on video in 1987 under the title El lago de las virgenes (thanks to Álex Mendíbil for clarifying the matter).