There used to be a flying course over on Fountainhead Island. It started at the ruins on the far side of the island. It was good for learning how to control the griffin's flight, but for some reason, they took it out. There was also a course in the underwater cavern for the azartash, but I could never coordinate the az well enough to maneuver through it.
What you have above is a graphics problem. There are a lot of incomplete rocks in Wander. I've posted quite a few of them, but the devs seem to have bigger fish to fry. On Dryad Island a lot of them are over in the Griffin's Roost area, but almost ALL of the caves have incomplete rock issues. I hope they get around to fixing these at some point. They are all over the game.