The stone of recall is attuned permanently to a particular location, its sanctuary. Up to a dozen individuals can attune to it at a time by holding it inside that sanctuary and speaking its command word. Later, if any of those individuals holds the stone and speaks the command word outside of the sanctuary, all of the individuals attuned to it are teleported back to that sanctuary. This also breaks the stone's attunement to those individuals, though they can then attune to it again.
Wondrous Item, uncommon (requires attunement)