Guide:
Western Cyrodiil, just south of Fort Rayles.
Collectible on this side of the map is a part of Chorrol POI. This area stands out from other areas because, it is a place where you can find lave river. There are many buildings in this area. Halion NPC plays a flute on the Chorrol square, beside a tall stone sculpture. For easier orientation, locate the wrecked tallest building in Chorrol, looking like an old Cathedral building. Next to it, in a lava riverbed, you can find the skyshard. Vicinity of a nearby Fort Rayles can make the problem, because of many hostile players.