This study examines Iranian English language teaching (ELT) Prospect textbooks in light of the recently developed discipline of Cultural Linguistics. Cultural Linguistics is a field of research that explores the relation between language and cultural conceptualisations. The Cultural Linguistics ethnographic-conceptual text/visual analysis methodology is employed for the analysis of the cultural conceptualisations embedded across texts and visuals. It is revealed that lesson 3 of Prospect 3 captures the Iranian cultural conceptualisations of Nowruz and represents it as an event for (a) renewal of human beings and reinforcement of human relationships, (b) joy, (c) wishing good luck and avoiding bad luck, and (d) visiting. The current research has significant implications for both research and pedagogy in ELT.