Mhair Jungles

The Mhair Jungles lie between the Lapal Sea and the West Wall of Halruaa. This expanse of dark, tropical forest contains all manner of plant, animal, and monster life—most of it unknown anywhere else, and much of it deadly. The yuan-ti, who consider these jungles sacred, come here to hunt, scour the ancient ruins of their ancestors, and drive off intruders. The northern Mhair Jungles are also the preserve of dire tigers, digesters, and many nomadic tribes of wild dwarf hunters. The wetter southern reaches eventually give way to vast mangrove swamps hunted by solitary sword spiders and nagahydras.
Yuan-ti dwell in and among the ruins of Mhairshaulk, and other major ruins are claimed by solitary Faerûnian ha-nagas and nagahydras. Lesser ruins are uncommon on the surface because the jungle growth has wholly devoured them over the course of millennia. Scattered sinkholes throughout the Mhair Jungles lead into the Serpent Deeps, and explorers are advised to watch out for sinkhole traps set by dwarf hunters.