Beyond the mountain range of the forest lies a lovely fertile valley that would make prime real estate for a sanctuary perhaps, but has been left untouched ever since the Night of Falling Stars. The southern tip of the island has been impacted by a massive crater. The darkness which still hangs inside keeps the ocean waters at bays, for despite the fact that even the part of the island connecting to the sea is gone - no water seems to fill it. Above remains an ever-floating island, similar in fact to the grand city section of Echelon of Ferelden. Not many people have returned from many attempts to climb or ascend that floating rock, its top wreathed in mist it remains a mystery to if anything is up there. Not many can stick around for nights an mornings in the valley are accompanied with wails seemingly wafting from the mountaintops. Whilst unnerving to few, this place has, in fact, been home to stragglers, strays, exiles, and others. Once you get past the nightly alarming wails, it can get quite lovely here. To top it off, some people who have made it to the valley in haste or desperation say that walking inland more you might go mad an end up finding some safe haven. Keeps you well rested till you keep walking to the other side. Somehow, they always end up making it off the island, but one person that did go back say they never end up finding that safe haven which once welcomed them before.
Yezzeveil forest consists of tropical an fungal trees, rapidly mutated. Consists of regular tropical treelife but has been rapidly overtaken by a network fungal growth. They are parasitic an capable of latching onto, an eventually taking over the tree's function. These fungi have grown magically to accept sunlight straight after consuming the trees they are on. The same function seems to extend to the Myconid race that calls this section of the island home. Various explorers have cited the earlier travels of Myconids to demand sacrifice to be allowed access to their forest. Enough of these sacrifices seem to have grown the Myconid species into now more communicative creatures.
Thankfully as they have stayed landlocked, the Myconid has not spread out to any other parts of the island or other islands, but the appearance of fungal-infused humanoids, humans, dragonborn, elves, remain unnerving to people as they are kept wary. The bravest or mad still venture into the Myconid forest for its very rare synthesized plantlife. It has been proven by one mad academic that this myconid forest is capable of growing almost any kind of plantlife.
Meals were made to keep the Myconids away, for whilst they do have some small currency from ill-fated travelers, Myconids seem to trade in pheromones & chemicals. There's even a running tall tale that bags of fertilizer could be used as payment, but you'd have to speak to local sailors to confirm or deny that.