A result of The Shatter that has caused all manner of problems for the inhabitants of Vilra-Shal, while called Shimmer Mirrors, they are fractures in the mortal plane - unstable portals left over from the merging of the planes. - Incomplete slices in the world that failed to merge and cannot stabilize.
The most commonly found mirrors are fairly small and can't maintain their existence for long, often appearing and fading before anything happens; these tend to mostly take place around the natural parts of the world rather than inhabited areas. Something about altering the natural world and building structures seems to stabilize the area nearby, though this is not a proven fact, and there are still many reported cases of them appearing inside of settlements. The size of these smaller mirrors does vary but never exceeds a large doorway, and each Mirror also seems to connect to a different plane, though this has only ever been measured by what comes through the Mirrors by a few.
However, there are a number of locations that have permanent, larger Shimmer Mirrors. Some of them were behind closed doors, others openly studied, and some were left abandoned due to their often dangerous nature due to the instability that they have demonstrated in their time. Much of the area surrounding the large Shimmer Mirrors is far different compared to that of the flora and fauna; as these Mirrors have remained for so long, much of the world on the other side has transitioned to the side of Vilra-Shal. Naturally, the world on the other side lives by different natural laws, causing some of them to have immense and unusual properties not found in the plane of Vilra-Shal. This naturally has caused the curious and power-hungry to gather around the permanent Shimmer Mirrors, hoping to gleam the knowledge or power from them.
