Hazelmere's island is the island where Hazelmere the gnome lives. His house is on the southern end of the easternmost island in this small chain. The gnome can be found on the top floor of his house, unless you have passed a certain point in While Guthix Sleeps.
The island is also referred to as "Jungle Spider archipelago" or "Green spider archipelago", named after the Jungle Spiders that inhabit the island.
One can use the Fairy Ring code CLS for quick transportation to and from the island. The Fairy Ring is located just behind Hazelmere's house.
Hazelmere dies during the quest While Guthix Sleeps while fighting against Lucien. Currently if a player is doing Treasure Trail after the quest and are asked by a anagram to speak to him, they will be unable to do it due to his death. Players distraughtly must abandon the clue, for there is no current way to continue it.