There is a ledge overlooking the pool above the water level, on the south wall. Ahead, on the left is a large rock with a frostbite spider in an alcove just behind it.
Following the path around the pool and it takes a couple of turns before passing the ledge. Thick cobwebs cover the front, that you need to hack or burn.
Here first two frostbite spiders, and then three more will converge and attack.
On a pillar in front are several more glowing mushrooms.
The path turns west just by the rock and continues to descend.