For the sake of not killing my overly-curious PC's, could anyone by chance suggest an artifact of equal power that won't kill everyone as soon as it meets contact with sunlight, but was possibly still intended to kill everyone in the surrounding area?
Scroll of Apocalypse from the Sky and some random artefact ?
π = 4
Consider a 5' radius blast: this affects 4 squares which have a circumference of 40' — Actually it's worse than that.