I hope when he changes zones that he either:

Makes those small cavelike areas visible on the map
OR
Make those caves have mobs or loot or gathering points that actually give something special, that way even if you can't see them on the map, because they give something special they could be considered 'secret spots' or something like that.

Because at the moment I feel like exploring into one of those caves that I can't see on the map is kind of a waste of time, and sometimes I have to go through them to get to other areas on the map that don't have any obvious route.