I was thinking of an area where I could go to if I was stuck at a quest and wanted to figure out how to finish a quest. A library-sort kind of stage where information would be available. Information could be presented via pictograms, probably similar to the walkthrough feature of machinarium (you can play the demo at machinarium.net/demo/) where it is presented as drawn pictures with no accompanying text (screenshot at i.imgur.com/dedBy.png). Or maybe information may just be in the form of hints.
However, I'm aware that having such a place may lead to players visiting it all the time, so to balance its use, maybe it would require one to pay currants to enter. Or it may be open only at certain times. Or it could be a moving/walking library. Or a library card can be used to access it for a specific number of times.
It could also contain a section where additional more complex quests (which give higher rewards) can be found. There could be a selection of quest and the player can decide which of these quest he would like to pursue. The quests are separate from the ones given by the rock.