After acquiring the Amethyst Paragon by defeating a frost giant in the Vale, the Dragonborn will be able to use the Paragon Platform to access a previously inaccessible section of Darkfall Grotto, which is a small spire located beneath the main waterfall. On top of the spire, there is a chest with random loot (usually high-level gems).
After dropping into the lake, on the right side of the waterfall, there is a small camp where feral Falmer have apparently killed the resident Falmer. They are accompanied by small numbers of chaurus hunters.
- The initial way to access Darkfall Grotto is by falling down the waterfall located at the south-eastern end of the Forgotten Vale's frozen river; after falling down that waterfall, the player will be taken on a short water-slide-esque "ride" through the caverns. This function of fast-moving water in a dungeon was the result of the Skyrim Developer mod week, when one of the tests involved a moving-water dungeon. The water slide eventually leads out into the large cavern in Darkfall Passage.
- When going down the water falls/slide in the above with Serana, she comments, "Next time I tell you not to go down the waterfall, listen to me."