The Hobe Fort in Tamsui which has multicultural history of Qing, Japan and the present day is the cultural heritage in Taiwan. It faces issues of authenticity after several plans of preservation and reuse by the governing authorities on Taiwan. The purpose of this study is to make the history of the Hobe Fort clear by making good use of historical documents held at Toyo Bunko, Japan Center for Asian Historical Records, and The National Archives of the United Kingdom. The pursuit of authenticity in the conservation of the Hobe Fort is to check the location, guns, architecture and space. To develop the culture tourism based on the true history. The study shows Hobe Fort’s geopolitical relation from the Battle of Tamsui of the Sino-French War, history of guns, and original of Qing.