The self-concealing of being is a primary preoccupation of Heidegger's later thought, but neither Heidegger nor his interpreters have made clear precisely what it is. In this paper, I identify the self-concealing of being as the concealing of the worlding of the world, which is essential to and simultaneous with that worlding. In order to establish this, I sketch a taxonomy of the various phenomena of concealing and concealment in Heidegger's work by building on Mark Wrathall's four ‘planks’ of unconcealing (...) and concealment. Importantly, I distinguish the procedurally prior concealment that all unconcealing presupposes from the simultaneous concealing that Heidegger frequently confuses it with. This distinction not only allows us to get clear on what it means to say that being conceals itself but also reveals various confusions and obscurities in Heidegger's own thought as well as in that of his readers. (shrink)