In addition to featuring in the title of that work about one called Xiros by Cortazar, this word pluralized is contained in the title of a novel in which a painter named Thomas Hudson dies hunting for a German sub in its third section "At Sea;" that work also features the sections "Cuba" and "Bimini" and was reconstructed from Hemingway's manuscripts.  
One of these is the title object of a short story that Marini is fixated on, but he dies in a plane crash before he can ever visit it.  In addition to featuring in the title of that work about one called Xiros by Cortazar, this word pluralized is contained in the title of a novel in which a painter named Thomas Hudson dies hunting for a German sub in its third section "At Sea;" that work also features the sections "Cuba" and "Bimini" and was reconstructed from Hemingway's manuscripts.  Another work with this word in its title features a stereotypical Irishman named Matt Haffigan, who joins Tom Broadbent to develop land in Rosscullen; that work is titled after John Bull's "other" one of these, and a "mysterious" one titles Verne's follow-up to 20,000 Leagues Under the Sea.  FTP, name these geographic entities in literature like the one "of Doctor Moreau" in a Wells story.
One of these is the title object of a short story that Marini is fixated on, but he dies in a plane crash before he can ever visit it.  
{island}s (not isles) (2) [AH]