Because the status of nature is ambiguous in Being and Time, we explore an ecological perspective on Heidegger’s early main work in this article. Our hypothesis is that the affordance theory of James Gibson enables us to a) to understand being-in-the-world as being-in-nature, b) reconnect man and nature and c) understand the twofold sense of nature in Being and Time. After exploring Heidegger’s concept of being-in-the-world and Gibson’s concept of being-in-nature, we confront Heidegger’s and Gibson’s conception of being-in-the-world and being-in-nature. It will become clear that Gibson’s affordance theory enables an ecological reading of Being and Time, in which the relational character of being-in-the-world is stressed and the exceptional position of human being-in-the-world has to be rejected. Moreover, it becomes clear that an ecological reading of Being and Time enables us to reconnect being-in-the world with being-in-nature (unconcealment), which is rooted in “primordial” nature as its infinite origin (concealment).