Level 4 is the fourth and the last Cathedral-style level in the original Diablo. The player(s) reaches Level 4 after from a stairway in Level 3. Somewhere in Level 4 there is a stairway to Level 5 (not shown on the map if tavern sign was stolen, see Ogden's Sign).
If available, the following quests can be done or initiated in Level 4:
The following monsters can be found in Level 4: