This article reads the work of English artist Paul Nash in the context of geological discovery in the early twentieth century and during the interwar period. The new knowledge of radioactivity followed by pioneering geophysical research in England, led by Arthur Holmes and presented in his book The Age of The Earth, transformed perceptions of reality itself. Nash’s work in the English landscape tradition was confluent with this new knowledge. This article describes Nash’s works beyond the bounds of extant modernist, neo-romantic and surrealist accounts. It also redefines the ‘Englishness’ of his oeuvre. When read as a geological realism, Nash’s work is visible as a rich precedent to realisms of the twenty-first century.