In a nearby town villagers tell tales of adventurers being driven mad by an unknown force within the woods…
When a local farmer discovers something at the bottom of his new well, the fate of the land will hang in the balance.
During their travels through a dense wooded area the high pitched sound of a scream tears through the peacefulness of the forest.
This mountain chain was once vast and impenetrable, but had the misfortune to named in the binding spell of a mighty demonic(godly?) being, namely that when the Great Mountains are forgotten, then shall it be free.
Real World: some Indians in the Amazon treat their eyes with a traditional potion applied with palm leaves. Brutally painful, the drug alters vision, giving the jungle's dense green walls greater texture and dimension. You could adapt this to desert or swamps, or other hard to navigate regions.