Secret fertile soil in Blue mokey room

[KingAzazel]

if you fall into the white river and find the secret room with the blue monkey NPC, interacting with the grave prompts the "fertile soil." text to pop up, which indicates that you can use the severed head in this spot, doing so brings you to a blocked off area in which you can see through some kind of coral door.

[SquishSquash]

There's another coral door over by Taski Maiden that's attached to a building. I wonder if they can be unlocked and if they're connected to Coral Glasses?