A mysterious magical artifact from the Forgotten Era. People have no idea how it works, or who was behind their invention, but life as most know it in Havenloft couldn’t exist without it. There may have been upwards of hundreds of thousands of these at one point, but now, after time and loss, they number only in the thousands.
Mysterious orbs of light and warmth. They look like small suns, floating above the towns that formed around them, providing a protective shield from the cold outside. Bizarrely, if you attempt to move them too far from their initial location, they will immediately go out. They can range in size, from small enough to hold in one’s hand to as big as a small building, and their efficacy ranges to match. Some lucky cities are in possession of more than one.
Fallen Suns provide the only reprieve from ice to be found in this world; the area within a sun’s protection not only experiences warmer weather (mid-late autumnal temperatures) but also protection from snowfall and heavy wind.
Every four years they need to be recharged - or stoked - by harvesting energy from one of many locations where multiple leylines converge with a stoking stone. However, since the leylines constantly shift, the only way to find them is through scrying. Some places pay handsomely, some places do it on principal. Should a fallen sun not be properly stoked they will burn out and fall to the ground; there’s no known way of reviving a dead sun.
Scrying for leylines is a form of magic, ritual, or prayer - a little akin to modern meteorology, in that there’s a level of interpretation required to make sense of the results.