In the dig site.
You see the entrance to Moriseli here on the right and the skyshard is behind some pillars to the left.
Where wolves prowl eastern ruins.
You can see the shining skyshard behind the ruin walls here. You will most likely approach it from above, rather than directly from the docks.
You can see the docked ship in the background.
Outside a house for the dead.
There is a quest on the hill above called “Unearthing the Past”. NPC that gives it is on top of a mound, beneath which is a crypt/tomb. Left of the tomb’s entrance is the skyshard (behind a tree).
Sand Kingdom Moons - Super Mario Odyssey Power Moons