Entrance to the spider cave
spider clan sentry guard
A cavern spider broodling
Legend told around scout camps at night: "It is unknown how a clan of Nightsisters came to inhabit a cave so close to the lands of their most hated foes, the Singing Mountain Clan. Those few who have ventured into the area and lived to tell the tale speak of large gaping spiders working as companions to the Spider Clan Nightsisters... helping with such things as daily chores and guarding the cave. The deepest recesses of the cave are home to the largest of the gaping spiders and even the Spider Clan witches rarely dare those depths. Only the web dancers venture into the deeper areas when in search of new spiders to train, but even they don't know what awaits in the darkest corners of the cave. Some say the cave is near -1200 6250."
This cave is home of The giant gaping spider, Kiin'Dray, and also home to Cavern Spider broodlings, which are more dangerous than the spider clan sentrys even though they don't aggro. Eventually you will get to the end of the cave and end up with an area filled with 7-8 cavern broodlings, and a cavern spider queen. If you kill all of these Kiin'dray, a CL 83 Elite monster will spawn and you will have a chance to fight him.
You have to visit the Nightspider Cult Cave during the Nym's Starmap questline.