Follow the only available path, which turns right after a few meters. After a while you'll pass by a chest containing a Phoenix Feather [!!!].
A little further there's an arena with an experience chest. There you will also have to fight a Centaur and a group of undeads. Overall it shouldn't be too hard.
The path will then lead through the place from which the Centaur ran down (perform some jumps through the rock ledges). The next stage begins a little further.