The Thunderlands are a particularly ancient forest in central Hellea. The region is inhabited primarily by Kheironoi centaurs and fey - the forest is one of the few ancestral lands of the centaurs that remains under their control. Clearings in the old growth forest are the locations of centaur encampments, orchards, and gardens, largely isolated from the broader world.
Outside visitors to the Thunderlands are tolerated by the centaurs though watched closely to ensure they do not attempt to settle in the forest or wantonly damage the natural environment. Though a rather uncommon event, on occasion the centaurs send out trading parties to the communities surrounding the Thunderlands.
Both Iaramnae and the city-states of the Halakran League have long claimed the Thunderlands as their own, yet neither exert any real influence with the forest. It remains too wild, and the centaurs too well-known for their archery, to be worth conquering. Still, with the once again inflamed tensions of modern Hellea, both sides have begun to move their forces and sometimes even skirmish around the margins of the Thunderlands, all while the Kheironoi watch them carefully, hidden amongst the trees.