本文討論清代文獻有關「後山」此一地理空間的論述與想像，文章整理有關「後山」此一地名的分布，討論臺灣東部作為「後山」時，其地理空間範圍如何呈現與變化。文章認為在官方的文獻論述裡「後山」除代表地方行政建置上的化外，也隱含前現代社會的文化階序；一般志書則視「後山」為半信半疑、匪夷所思、神秘不可測的自然力歸屬地，以透過未知地理空間滿足鄉民對異象的想像。

The paper discusses the discourse and geographical imagination of ”hou-shan”, or the back of the mountain, in the Qing documents. It first describes the geographical distribution of the place called ”hou-shan”, and then focuses on the changing geographies of ”hou-shan” as the eastern half of Taiwan. The paper argues that the official discourse presents ”hou-shan” as an uncivilized space beyond imperial administration, indicating a cultural hierarchical order in the pre-modem society. The Gazettes usually describes ”hou-shan” as a place where we expect to observe unbelievable or mysterious phenomena. In other words, ”hou-shan” as unknown geography greatly satisfies the folk imagination toward strangeness.