Home to the fabled Shining Towers, a gleaming beacon of light for miles around.
A short sidebar of encounter information for the fel Shadowbeasts.
A subterranean prison complex, meant to incarcerate those who need to be removed from society.
They will serve up the Light to appease their dark gods.
Believable magic, like ordinary physicis, operates according to some invariable laws that always result in some kind of cost or "bounce back". The grater the magic, the more it should cost the character physically, emotionally, and spiritually.