Guide:
Head to the southeastern part of the island, just east from the tower Enclave of the Hourglass and Strid River Wayshrine.
If you follow the southern Gold Coast shoreline, just before the area of interest called Varen’s Wall Gatehouse, you’ll spot a farm house. There are some agricultural fields, close to the house, edged with wooden fences. The one closest to the house has a field with many pumpkins. This is where you’ll find the last of outdoor skyshard. It has a rather unique name, and you’ll see why it named the way it is once you find its location.