In Heidegger's last seminar, which was in Zähringen in 1973, he introduces what he called a "phenomenology of the inconspicuous" (Phänomenologie des Unscheinbaren). Despite scholars' occasional references to this "approach" over the last 40 years, this approach of Heidegger's has gone largely under investigated in secondary literature. This article introduces three different, although not necessarily conflicting ways in which these sparse references to inconspicuousness can be interpreted: (1) The a priori of appearance can never be brought to manifestation, and the unscheinbar (inconspicuous) is interwoven with the scheinbar (appearing) as an active characteristic or form of "hiddenness" (Λήθη), therefore making inconspicuousness inherent within all phenomenology. (2) Or, there is now a particular step or reduction within phenomenology that involves one's being attuned to the various modes of potential hiddenness (Verborgenheit and its cognates), of which "inconspicuousness" is a particular character trait. Or (3) there are particular, unique, and specific phenomena that give themselves "inconspicuously," and there is also thus a corresponding, particular phenomenology in which one must engage in order to gain some kind of access to these specific things' phenomenal strata. This paper introduces Heidegger's "phenomenology of the inconspicuous" most especially in his last seminar in Zähringen in 1973, engages related references to unscheinbar in his 1942/1943 Seminar on Parmenides, and then puts forward an interpretation of what these somewhat ambiguous references could mean when