Cool. I'm not sure if anyone else has gotten that high up without being able to fly (ie after taking over the battle tower) or using the cheat menu in the Developer's Cut release of the game. I tried looking for a path mostly on the opposite cliff face, but gave up.
The rocks on that ledge are actually framing a door leading into the mine. If you visit the quarry tower north of there and talk to someone inside he will tell you about it, but you have to wait until you can do anything with that information. There are some opponents in the quarry tower that are at a higher level (difficult but possible, though getting out is harder than entering); in DKS and D2:DC the quarry tower is locked so you can not get in early.
