Kir was an ancient location on the planet Vulcan that was home to a Vulcan temple.
In "Falor's Journey", a Vulcan story, when T'Para offered Falor truth, he crossed the barren Fire Plains to get to the silent monks of Kir. Still unfulfilled, he journeyed home. (VOY: "Innocence")
The Star Trek Encyclopedia, 4th ed., vol. 1, p. 419 identified Kir as a province.