Within geographical research on ‘the body’, a focus on the surfaces of bodies, has been useful for considering how body boundaries, most often implied to begin and end at the skin, (de)limit, (de)regulate and (de)stabilise what we come to know as ‘a body’. Such work draws attention to how meaning is inscribed ‘upon’ such surfaces and on the fluids that move across, within and through those surfaces, for example blood, breast milk and excrement. This paper, however, considers the potential for thinking geographically about interior bodily surfaces by engaging with the placenta. The placenta is a temporary organ that forms in a woman’s body only during pregnancy and whose purpose is to mediate the flow of substances between a woman’s body and the foetus. It is often considered to have two surfaces, the maternal and foetal surface, or to be ‘a’ surface in and of itself. Our intention is to think geographically ‘with’ ‘the placenta’ in order to focus on what interior surfaces can ‘do’ rather than ‘what they mean’. In so doing our contribution is twofold. Firstly, it will focus on the ‘resurfacing’ of the placenta when it moves outside of the body to be placed upon other (bodily) surfaces, taken back inside the body of origin or put to use in research. This is significant for highlighting the specific mobilities and temporalities of interior bodily surfaces. Secondly, we consider the theoretical and ethical significance of the placenta for geography by engaging with Luce Irigaray’s account of the placental relation between mother and foetus understood as a space of mediation or ‘space between two’. In particular we are interested in considering the geographical potential of the sexed specificities of interior body surfaces, or their morpho-logics, for understandings of relationality, between self and other and body and world; in short, we work with the placenta as a ‘relational organ’ in order to uncover new and potentially enlivening ethical spaces of exchange.