Lake Ferona is an area in Breath of the Wild.
The lake can be found just west of the Maw of Death Mountain and northwest of the Foothill Stable. The water is very warm and will soothe Link back to health if he jumps into it. Despite its warm temperature, there are still some fish living in the lake, including the rare Sizzlefin Trout. Surrounding the Lake, there are some warm climate animals and bugs, including some Eldin Ostrich, Fireproof Lizards, and Warm Darners.
At the far west end of the Lake, there is a circle lilypads that Link can jump into to get a Korok Seed. On the north side of the lake, there is a circle of rocks with one missing. The missing rock is on the other side of the Lake and Link will need to carefully walk across the shallow water of the Lake to put it in its place. There are also some Luminous Ore Deposits on the south end of the Lake.
To the north of the Lake, there is path leading up the mountain with some Fire Chuchus. As Link begins to scale the mountain, large boulders will roll down and can knock Link back down towards the Lake.
Nearby Korok Seeds
Dive into the circle.
Blow up the boulders, pick up the rock.
The rock is across the hot springs to the southeast. Carry it through the shallow water.