Along with the dyad, here-there, we have to deal with 'near' and 'far' in matters of place. These are additional crucial ingredients in the relationship between body and place. Whereas the here and there are all or nothing, near and far comes in degrees of magnitude. They are complemental in the sense that "the more of one, the less of the other" (p. 57).
Heidegger uses near and far in his discussions the ontic difference. The ready-to-hand is ontically far in its withdrawal and ontologically near in its execution. The present-at-hand is ontically near in its mere presence and ontologically far in its mere objectification. Later he gives these a more involved treatment in discussing the bridge in Heidelberg in "Building Dwelling Thinking". Like a lot of Heidegger's work, it's a workout to get your head around the nearing that nears and so forth. You might get more understanding from Grover.
The near and the far exhibit "changing aspects of the situations in which they are immanent" (p. 57). The perception of how near somebody is (existentially) to wildlands can shift with mood. If somebody is attuned to the wildness existing in their immediate environment then wildlands might feel more near. Far and near can have different notes depending on the emotion or tone of what is to be encountered in the near. "More than any other dyad, the near--far is attuned to--and thus reflects--the particular way I am inserted into my life-world at a given moment"(p. 58).
Because the near and far are so colored and influenced by attunements, "they are especially averse to exact determination of a metric sort….Indeed, any effort to measure the near or the far--to gauge them, singly or together, on a scale of uniformly distributed marks or numbers--not only misses the phenomena themselves but undermines their very identity" (p. 58). Despite his work on a place attachment scale, Dan Williams (2014) acknowledges that there are more productive ways to explore place meaning. In addition, because of the influence of attunement, "the near--far is thoroughly spatio-temporal in its experience and presentation." Things and places can feel near and far in both space and time.
Structures of the near and far
The near consists in the realm of 'reach'. Reach could be actual or potential. Things within actual reach are ready-to-hand. The criterion for reachable nearness is 'advertability'. Advertability, Casey says in a note (p. 391) is from Shutz and Luckmann (The Structures of the Life-World, p. 37). Whatever is in actual reach "embraces not only actually perceived objects but also objects that can be perceived through attentive advertence." Advertence is "the quality or practice of being advertent; heedfulness" according to the American Heritage Dictionary. So places can be near to the degree that we pay them heed and take them into our regard. The potential reach of the near is "all the rings we could reach" (p. 59). There's also 'restorable reach' but I'm not too sure about it and I invite anyone to describe it more fully for me. And there's what's in the 'attainable' reach based on already understood situational typifications that may or may not come into my direct environment but can be sensed in the greater environs. Casey's example is hearing a cat fight outside, understanding it's execution, but choosing not to draw nearer to it. The "near sphere, then, is a nexus of differentially available reachables, connected and traversed by pathways" (p. 60). And any place has an "implicit infrastructure" via "a pattern of nodal points…and connecting paths" (p. 60). Thus there is a new specific intentional arc: "an arc of reachability stretching between my body on one hand and pathways-cum-reachables on the other" (p. 60).
What does Casey tell us about the far? The far is not on account of distance. To experience the far is to have an experience of range. The near is to reaching as the far is to ranging. To be a constituent of wilderness and to constitute a wild place in everyday life is to have an experience of the far. This is because "it can occur in a purely perceptual (or memorial or imaginary) mode whereby we transpose ourselves into the far and pick out features in it" (p. 60).
Being and moving the lived body in the far is an act of broad-ranging. Casey offers examples of broad ranging in sacred landscapes in which the 'far sphere' (far world, maybe?) is "filled with determinate religious experience" (p. 61). He also suggests an experience of the far world in Paris as a flaneur "exploring the byways of a far sphere that beckons without offeringv any definite purpose" (p. 61). The point is that the world of the far has room enough for planned and unplanned involvements.
The most prominent feature of the far world is the horizon. The horizon is more a boundary than a limit and this means that it cannot be attained or gotten to because it spreads out from land or sea to sky in its "recession in depth". He quotes Gurwitsch (1964 in The Field of Consciousness, p. 406) in noting how the horizon holds "things un-perceived, unknown, thing to appear in perceptual experience under the conditions of appropriate movement when we proceed in one or another direction."
It's also interesting to note is use of range in bespeaking the far. Heidegger has passages that trace words linked to "range" in terms of mountain ranges. I don't know if there is any connection, but it is in "The Question Concerning Technology" when gebirge is mentioned.
The horizon has near and far aspects to it. If a mountain range lies on our distant horizon what we perceive is its near-side. The nearness of that near-side is not within my near-world. "In this way I encounter a nearness of the far that belongs to the far itself" (p. 61, a nearness that is 'far-out, man!'). Another interesting aspect of the horizon is its withdrawal. The horizon is ready-to-hand. The horizon cannot be a mere object as present-at-hand. The horizon of the far world is "a boundary for objects" (p. 62). The horizon is very near to OOO. The lived body "requires" the horizon as possibilities prior its "pressing into possibilities" (Dreyfus 2007 lecture notes on Being and Time). It has to do with the future projecting and it is experienced as understanding. Casey quotes Derrida (1978, p. 117) "A horizon is always virtually present in every experience; for it is at once the unity and the incompletion for that experience--the anticipated unity in every incompletion." The ontological nearness of the lived body grants clearance to an approach to the horizon "there in its farness from the closeness my body realizes in each successive here" (emphasis added, p. 62).
The horizon "is the ultimate perimeter of places" and it serves as clear reference as the lived body moves in the near and into the far. "Moving--reaching and ranging--in the natural light of the horizon, we encounter the places the horizon itself makes possible" (p. 62). We now add to the first two kinds of intentional arc, tensional and reachable, the horizonal arc that contains all with-in the near and far worlds. The most effective interaction among body-horizon-place lights up before the horizonal arc. Every place fluctuates in the near and far for Dasein. This is true because Dasein is the being "for whom the near and far, along with the here and there, are inherent features of an embodied experience" (p. 63).