Historically, most medicine wheels follow a similar pattern of a central circle or cluster of stones, surrounded by an outer ring of stones, along with "spokes" radiating from the center out to the surrounding ring. Often, but not always, the spokes may be aligned to the cardinal directions. In other cases, some stones may be aligned with astronomical phenomena. These stone structures may be called "medicine wheels" by the Indigenous nation which built them, or by more specific names in that nation's language.