Guide:
Northwestern Reaper’s March, north of Fort Grimwatch Wayshrine, within Old Town Cavern POI – crafting camp.
Heading from south toward this location you can notice the shard inside what looks like an awesome tree house. In order to reach it you should proceed toward the center of Old Town Cavern. This is a crafting camp. There are cellar doors at the center of a camp. You can craft 3 piece “Night Mother’s Gaze” set here. Three set items give critical attacks and also reduce the targets armor by 20% for 5 seconds.
Near the cellar entrance to crafting stations is a path that leads toward the collectible. There are couple of level 37 Skeevers defending it.
You have to go up a tree-ramp that’s a couple of trees away from the shard.