The Uncharted North
Situated in the frigid northern reaches of Leng, the Uncharted North is one of the most dangerous regions on the continent. Vast territories are ruled by jealous dragons that constantly squabble and vie for power, and all kinds of beasts both wondrous and terrifying can be found amidst the broken ruins of civilisations long fallen. They are rightly called the monstrous lands, for it is here that the King of Goblinkind reigns under a vast low mountain range; it is here that the broad territory of the cunning Grey Trolls stretches. Here it is that in the highest mountains the remnants of the Gigantine Kingdoms still reign, and here settlements and towns of marauding ogres can be found. It is a land untamed and untouched by humanity, where the worst fears of mankind are realised; a land where the only civilisation to be found is monstrous and evil.
South of the Uncharted Lands, the most obvious passage between the south and north of Leng is obstructed by the infamous Plains of Death. Called forth by the Gray Trolls during their siege of Uzan Rith, it is a region that is so blighted by foul magics that it remains a locus of evil to this day. By day it is safe enough, though completely devoid of life. When the sun sets, however, the bogeymen arrive. The bogeymen are the spirits of those who have died in the Plains of Death. They fight as shadows, but have physical form and appearance at night: clawed and scaled humanoid monsters. Some have wings and can fly, or horns - or other diabolical features.
As long as the sun has set, they emerge from the very darkness itself to accost anything living. Only bright light, as of a full-on bonfire, is enough to keep them at bay. Even so, they will cluster at the edges of the fire and gibber and shriek, making it impossible to sleep. Even if the bogeymen do not get you, sleep deprivation is enough to drive some to madness.