Gwyrwood

Fold mountains are created when one tectonic plate folds under another. When this happens, especially when sparsely-populated, Reality can become trapped within the folds, creating a type of thin place - places where people can step from Reality into Dream, and vice versa. People who go through into Dream may come out anywhere between an hour before they left to a hundred years later, if they emerge at all, and the time they spent in Dream does not correlate to the time elapsed in Reality. These areas are found worldwide and have many names; in the area of the Daïdänt mountains, they are known as gwyrwoods.

A gwyrwood differs from other thin places in the level of danger it presents; the Dream-denizens of the gwyrwoods are overtly hostile to the denizens of Reality. It is hardly surprising that the Gwdaïdän have a profound caution around them, adopting traditions and superstitions to help them coexist with their dangerous neighbours.

One of the traditions is to keep a respectful distance. While the Dream-folk generally remain on their side of the boundary, they are also drawn by the proximity of mortals. Gwyrwoods are marked with cairns and strings of windchimes; the chiming of metal is believed to deter the Dream-folk. Despite these precautions, under certain conditions - lunar phases and eclipses, for example - Dream-folk cross into Reality to hunt and, when lone travellers and incautious goatherds disappear at these times, it is assumed that they have fallen prey to the Dream-folk. But the hunting of mortals is not a one-directional transaction: mortals travel into gwyrwoods in order to hunt, too, looking for magical artefacts and reagents, or revenge.