i know it sounds silly at that lvl but i found it interestingly frustrating to get high enough lvl to do the pit.
what i did was the spider cave till around 5 and then i was able to move to pit i believe, stayed there till 12, kurns till 20....etc etc
its "D" on the map
http://wiki.project1999.org/index.php/Field_of_Bone
when you go down there is a single spider just inside the entrance, the room to the left is atleast a 2 pull sometimes you get all 5 of them, first room to the right is a double pull, last room on right can be split into 2 pulls i believe and the tricky room is the biggest one straight at the back. alot of roamers and 2 stationary i believe on the left side, just time it and you can probably get around 2 alone.
lol at spending so much time there that i remember all that...