At night-time there is an area by the first aetheryte where the texture or lighting is bugged on the cliff face. There is noticeable seems in the textures that make it look like it is unintentional.

Frequency: Always at night
In-game time: Happens at night
Area and coordinates: The Lochs ( 11.4 , 19.9 ) Z: 0.1

Steps:
1. Wait till it's nightime at area.
2. Look for the obvious seem on the cliff face at the co-ordinates.

https://imgur.com/g0MxvTR