In order to reach the skyshard look for the stairs in the Western part of the temple. Use them to reach the upper floor and a platform where the main Temple room is located. At the eastern side of the temple you will find the Southern temple’s hidden jewel Skyshard.
Southern Khenarthi’s Roost. Head Northeast from Khenarthi’s Roost Wayshrine towards Temple of the Crescent Moons.