In 2011, the University Museum of the University of Tokyo gifted the digital files of a total of 221 historical topographic maps of Taiwan from their collection of Gaihōzu (Japanese imperial maps) to the library of National Taiwan University for the purposes of academic research and promotion. Gaihōzu, as coined by the Japanese academia, refers to the maps of foreign lands plotted and replicated by the Japanese military or other units for military purposes, dating between the Meiji Restoration to before the end of the Second World War. Before the war, Taiwan was a Japanese colony, and thus included in the territories covered by Gaihōzu.

In recent years, Gaihōzu have received newfound attention in academia. With gradual compilation, cataloging, and digital collection, these materials were made public and became important historical archives for research on the evolution of East Asian geography before the war. In 1895, the models for plotting topographic maps were introduced to Taiwan. For the past hundred years, several dozens of map series ranging from large-scale survey maps to compiled small-scale topographic maps were created, essential in the recording of the geographical evolution of Taiwan.