This chapter defines the landscape of genius: literary landscapes in which the genius of the author became associated specifically with nature. It focuses on William Wordsworth’s association with the English Lake District and Henry David Thoreau’s association with Walden Pond as paradigmatic landscapes of genius in the British and American environmental traditions, respectively. Wordsworth’s connection with Lake District nature was widely celebrated in nineteenth-century Great Britain and the United States and strongly influenced Thoreau’s identification with Walden. The chapter traces the historical development of those two landscapes of genius and the wider impact of their authorial associations. It explores how the Lake District and Walden Pond emerged as iconic sites for the development of an environmental movement, which sought to preserve such landscapes and their high-cultural associations from modern economic and technological development, as well as from the incursions of the urban working class and popular culture.