Guide:
Southwestern Shadowfen, south of Loriasel wayshrine, west of Venomous Fens Dolmen, southeast of Xal Ithix.
Located inside the “Chid-Moska Ruins” solo dungeon. Start at Loriasel Wayshrine and follow the road going south. It will lead you straight in front of a stone ziggurat. The entrance to the dungeon is on the top. This skyshard is in a small room, located at the bottom right part of the tunnel turning north toward a big room.
This is not a solo dungeon so you might want to change the description.