Guide:
Southeastern Eastmarch, east of Jorunn’s Strand Wayshrine.
Inside The Bastard’s Tomb public dungeon. Start at Jorunn’s Strand Wayshrine and head east and slightly south, toward the hills. You will see a wooden door, illuminated by a torch, leading into the dungeon.
This skyshard, like the other Eastmarch solo dungeon shards, has had its location changed due to post-launch dungeon remodeling. What you are looking for is in the northern part of The Bastard’s Tomb. Turn left from the entrance and head to the northeastern part of the room.