This paper analyses social constructions of nature in different discursive contexts and the ways in which particular representations of nature are used to legitimate specific institutional policies and practices. The proposal to create a commercial and entertainment development on the Rainham Marshes Site of Special Scientific Interest (SSSI) in east London provides the case study. Drawing on arguments from media sociology and the sociology of risk, the paper explores the identification of distinctive myths of nature associated with particular sociopolitical formations within the discourses of developers, conservationists, the media and the public. Detailed ethnographic research reveals how the developers and conservationists employed different constructions of nature to justify their respective positions and how different local audiences made sense of competing claims about the relative worth of the 'nature' on their doorsteps.