The surface of the Lake Lost to the Sun is a twisted reflection of the sky: it might display clouds on clear days, thunderstorms amid calm weather, or a starlit sky when the sun shines. No vegetation grows within 50 feet of the lake. The water smells like a bile and honey mixture, and tastes bitter.
The Lake Lost to the Sun is one of the deepest non-oceanic bodies of water on Golarion. Beyond 1,500 feet under the surface, the Material Plane and First World begin to blend, and by 3,000 feet deep, the lake transcends entirely into the First World. Despite its apparent stillness, it is difficult to swim in the Lake Lost to the Sun, due to numerous invisible currents and eddies, and these swimmers risk catching a curse like that bestowed upon the killer of a fjord linnorm, or inadvertently passing into the First World: as they rise to the surface, they find themselves on the shore of the Cerulean Sea, Ragadahn's home on the First World. However, this phenomenon never happens to those who actively wishes to travel to the First World.
Those who use the surface of the Lake Lost to the Sun to cast scrying spells can see into the First World and the Material Plane alike, but risk having their mind twisted by Ragadahn. Due to Ragadahn's taint, both Sarkorian Green Faith druids and Worldwound demons have avoided the Lake Lost to the Sun.
The Lake Lost to the Sun is home to numerous intelligent, fey water orms, ruled by Ilirjastehr, a particularly powerful fjord linnorm that serves as Ragadahn's proxy. Most intruders are brought by Ilirjastehr to Ragadahn on the First World, although nothing prevents her from destroying them outright if she wants to.