 Cultural geography. Cultural geography is a subfield within human geography. Both the first traces of the study of different nations and cultures on Earth can be dated back to ancient geographers such as Ptolemy or Strabo. Cultural geography as academic study firstly emerged as an alternative to the environmental determinist theories of the early 20th century, which had believed that people and societies are controlled by the environment in which they develop. Rather than studying predetermined regions based upon environmental classifications, cultural geography became interested in cultural landscapes. This was led by Carl O. Sauer called the father of cultural geography at the University of California, Berkeley. As a result, cultural geography was long dominated by American writers. Geographers drawing on this tradition see cultures and societies as developing out of their local landscapes but also shaping those landscapes. This interaction between the natural landscape and humans creates the cultural landscape. This understanding is a foundation of cultural geography but has been augmented over the past 40 years with more nuanced and complex concepts of culture, drawn from a wide range of disciplines including anthropology, sociology, literary theory, and feminism. No single definition of culture dominates within cultural geography. Regardless of their particular interpretation of culture, however, geographers wholeheartedly reject theories that treat culture as if it took place on the head of a pin. Among many applicable topics within the field of study are globalization has been theorized as an explanation for cultural convergence. Westernization or other similar processes such as modernization, Americanization, Islamization and others. This geography studies the geography of culture. Theories of cultural hegemony or cultural assimilation via cultural imperialism. Cultural aerial differentiation as a study of differences in way of life, encompassing ideas, attitudes, languages, practices, institutions and structures of power and whole range of cultural practices in geographical areas. Study of cultural landscapes and cultural ecology. Other topics include sense of place, colonialism, post-colonialism, internationalism, immigration, emigration and ecotourism.