You can find a lever (needs the ancient key) in the room with the altar that will open a secret passage where you can find some decent treasures. Imp Temple: There are two Black Ring Wargs playing with a red gem just west of the Lunar Gate waypoint (X:275, Y:824). Either persuade...
With them all dead, leave Hans alone for now and go near the stairs you entered at. Look for a Lever near there, and use it. This will reveal the way to the Ancient Passage. Enter and take care of business there. Once you return, go UP the staircase just near there. First Revisit...