Looking for sky boundaries (Lake Urmia, Iran)

Horizon disappearing above one of the largest permanent hypersaline lakes in the world (Urmia Lake, Iran). Some flat crystals are floating on the undisturbed surface, while you can actually walk on a thick accumulation of salt crystals on the floor. The surface area of the lake dropped to less than 10% of its original extent 50 years ago, and now the salinity can exceed 300 g/L.