The topographical section of the Ordnance Survey in Ireland (1824-1842) produced a monumental study of the language, history and culture of Ireland. This chapter argues that the Survey, while often derided as an act of colonial appropriation and criticised for its inelegant translations of place names, was a crucial institution in the formation of Irish literature and in the construction of history and memory. The Survey’s many afterlives shaped the course of literary production in the nineteenth century, and three of those afterlives are briefly sketched out in this chapter. From the Survey’s preservationist attitude to the Irish language, to its part in the growth of a positivistic school of historical research and its hand in establishing the Aran Islands as a fount of an imagined national culture, the impact of the Survey is not far to seek in Irish culture in the nineteenth century.