Of all the corporeal functions that underground infrastructures support, the sewers and the removal of waste remain the most ‘invisible’ and unrecognised in the representation of the modern city. Perhaps the relegation of this most essential system speaks more of contemporary society's approach to human excrement: something to be forgotten with the first flush, an object to be eliminated from the home and diverted to the outskirts of the city, a solid that should be sublimated in some state-sponsored plant as we wash our hands clean of it. However, in all these elisions, the underlying rhetoric that permeates excremental (non)discourse is clear; the effective removal of filth and waste from the body of the city is essential in forging and maintaining social, psychological and cultural boundaries. As Alain Corbin maintains, ‘The urban physiology of excretion constitutes one of the privileged means of access to social mentalities.’ By privileging the sewers and following the flow of their rationalisation in nineteenth-century London, this chapter attempts to unearth the links between the development of the underground sewer and its seeping impact on the surface of the city, from the spatial reorganisation of the urban landscape to the cultural formation of the sewer in the social and literary imagination.