The Trackless Wood
In the heart of Ariath lies an ever-changing, unmappable forest. The Trackless Wood has existed for as long as any histories remember, and it is immense enough to swallow whole kingdoms. It's one of the most magical places in a world steeped in magic, and it contains so many wonders and terrors that no lifetime would be long enough to see them all.
Beasts, monsters, harrows, wild magic, tribes of Wicked wood goblins, and many other hazards make the Trackless Wood a dangerous place. Still, for Folk wise in its ways and willing to keep to themselves, it can be a good home. Food is plentiful, as the gods meant it to be, and shelter can be made if one knows which trees have spirits, and which are safe to cut down for wood.
By ancient treaties, no nation may claim the Wood, and as a result it is home to many Folk who'd rather be left out of wars and politics. A handful of major towns, countless small villages, and many isolated homes can be found under and between the ancient trees. No laws hold sway over the Wood but those of the gods, and justice is mostly left to the few Faithful of Sorrow who call it their home.
The Paths in the Wood change from day to day. People who know the place well can find their way from one place to another within it, but the way is always different. Folk with true skill can use these Paths to lead excursions far afield, and emerge from them on the edge of any wood in the world. Some people claim that every wood in Ariath is part of the Trackless Wood, and who's to say they are wrong?
Deep in the Trackless Wood there is a town unlike any other. The stories call it Covenant, and it waits empty under the boughs for decades or centuries at a time. Folk can find it when they need to, but few stay for more than a day or two before moving on; most feel uncomfortable, not as though they are in danger, but as though they have overstayed their welcome and should politely depart. But on rare occasions, Folk find themselves welcome there, and even travel there from great distances to make it their home. Nobody knows why Covenant calls to these rare souls, but its doors are open only in times of calamity, great war, or ill omen. If the lamps are lit in the Covenant's Hearth, and smoke is rising from its kitchen stacks, all Folk know that one day stories will be told about the coming years, for good, or for ill.