nubbsgalore:

a waterfall of mist flowing over golden cliffs of west bay in dorset. noted the videographer, “when i walked on to the beach i couldn’t see anything because of the fog. i could barely see the top of the cliffs. i sent up my drone well above the cliffs to see what was happening and i could see the fog just flowing over the cliffs like a waterfall. 

normally, hot air will cool as it rises, but the opposite can sometimes occur in what is known as temperature inversion, where hot air high up acts as a seal to keep cold air and fog trapped below, creating the scene of a river of fog seeming to flow into the sea below. (x)