CityCairns are one of the most important artifacts in Elventi culture, allowing for cities in harmony with nature. Six or more surrounding an area creates a slight field of mystical energy. This field insulates the area, keeping it from getting too warm or too cold, and deflects most rain and snow. (Seeing the rain/ snow slide off the “sky” to the side can be an interesting site.) A set of cairns defines the general boundaries of every Elventi city. If one is lost to accident, the area scribed by the remaining cairns will remain protected, unless there are fewer than six. Then the magical protection fails and the full fury of the elements can touch the delicate Elventi city.
On Arth, Every Elventi city and most Humanti towns/ villages on FirstLand is protected by a set of cairns.
Like Hearthstones they must be enchanted to a specific biome, in that specific biome. They can not even be moved, once they are in place.
A cairn must be tailored to its city and environment, so there is no “one description” of these items. They are made of stone in any permanent location (wood in “temporary in Elventi terms” locations). Each cairn tends to be .5 to 1 meter (19” to 39”) tall cylindrical poles (or similar shape). The pole is .2 to .3 (7” to 9”) in diameter with a flat top. The top has a series of intricate knotwork symbols that binds the magical forces to it in connection with all the other cairns.
Now some look like poles, other pylons, other small table, yet other stone mushrooms. Some are quite plain, while others are decorated. They tend to be hidden in out of the way places around a city.
The Elventi have been using Cairns for so long, they do not properly know the origin of them. They were made to initially protect sacred groves or work spaces. They were then expanded to protect “The Places” where the Elventi lived. They are one of the earliest magic enchantments the Elventi mastered.