Start by heading up past where the crystal eyes camp is and going through the false wall. Head back a bit and then jump down. Jump down again into the trap room with 3 dogs.
Go up the ramp to the first room and turn right. Once in that room turn left again.
Once again turn right and go up another ramp. Forwards and up a ramp.
From here keep going forwards until the room just before the specters. In that room look to the right, you should see spiders 2 rooms down.
While nothing spawns in the room before the spiders, there are quite a few things around that area that may agro if you camp there.
Also worth noting, quite a few things along the way see through invis.