The Tower of Cirith Ungol and Shelob's Lair

Inside book summary: "Within a reeking, dark tunnel at the summit of the pass lurks a primeval monstrosity, the devourer of Men and Elves -- Shelob, the Greatest of the Great Spiders. ... On one side of the bridge of Minas Ithil stands tall and proud, offering refuge and pleasures. On the other side lie perils of Cirith Ungol and Mordor, where the valiant and skillful may win renown -- or lose their lives trying!"