Guide:
In the heart of the ruins located in western Vvardenfell, in the area of interest marked as Ashalmimilkala on the map, west from the Balmora settlement and its wayshrine.
If you find yourself in this zone, you’ll spot two areas of interest close to each other. The southern one is Ashalmimilkala, while the one in the north is Aleft. They represent old Daedric ruins. Go toward the southern one.
If you approach it from the south, the skyshard’s glow will become noticeable as you are about to enter the ruins. There is a door on this side, with a frame shaped like a semi-circle. It is as if the idea was to combine the glow and the frame into a perfect shape.
A decent number of Vvardenfell skill points are located near the seashore. Not a coincidence, considering that the coastline is rather long.