Entrepreneur Brothers co-founder Kuo Chia-chi has launched a website called "Taiwan Century Map," a tool that lets users enter a Taiwan address and compare a modern map with historical layers by dragging a slider across the screen.
The site offers six map periods: the 1904 Taiwan Fort Map, the 1916 Japanese colonial 1:50,000 topographic map, the 1921 Japanese colonial 1:25,000 topographic map, the 1944 U.S. military topographic map of Taiwan, and Economic Planning topographic maps from 1989 and 2003. It also generates a "100-year land ID card" that lists coordinates, the relevant historical era, and a landform classification, along with a short caption that can be copied to Threads.
Map data comes from Academia Sinica’s open WMTS service
According to the report, all map data used by the site comes from the GIS Center at Academia Sinica through its WMTS service. Kuo built the website after discovering that the map API had been made available free of charge.
BlockTempo said its own test of the GIS Center’s WMTS service showed an Access-Control-Allow-Origin setting, which means any site can call the map tiles directly without applying for an API key or negotiating a separate license.
The service currently lists 218 layers, while Taiwan Century Map uses only six of them. Other available layers include 1944 U.S. military aerial imagery, a 1945 U.S. military map of Taiwan’s cities, a 1930 geological map from the Japanese colonial period, official forest and field maps, and administrative district maps from 1901 and 1930. The report said the 1930 administrative version can show which prefecture,堡里-level division, and township a parcel belonged to at the time.
The article said public-sector institutions had already digitized these materials 20 years ago, and that open archives like these can now be turned into useful or interesting services with the help of AI tools.
The 1904 map was originally produced for land investigation
The report also reviewed the origin of the 1904 Taiwan Fort Map. In September 1898, the Japanese colonial government launched a land survey program in Taiwan to clarify land rights, classify land categories, and produce detailed topographic records for taxation purposes.
By 1904, the Temporary Taiwan Land Survey Bureau under the Governor-General’s Office had completed 457 maps at a scale of 1:20,000. Aside from 47 missing sheets near the fortress zones of Keelung, Kaohsiung, and Penghu, the rest were published in 1906 by Taiwan Nichinichi Shimpo, according to the report. It described the set as Taiwan’s first modern measured map series and a key source for questions about what the island looked like a century ago.
Three address tests all returned cultivation-area labels
BlockTempo tested three addresses:
- Taipei 101, No. 7, Section 5, Xinyi Road: classified on the 1904 layer as a "paddy and dry-field cultivation area" with 46% confidence. The accompanying caption read: "Back then, the hottest check-in spot here was the old well shared by the whole village."
- Hsinchu Science Park, No. 8, Lixing 6th Road: also classified as a "paddy and dry-field cultivation area," with 30% confidence. The caption read: "The price of this land 100 years ago: one chicken. Now: please take a deep breath."
- Taipei Main Station front shopping district, No. 49, Section 1, Zhongxiao West Road: also classified as a "paddy and dry-field cultivation area," with 54% confidence.
The report said all three results were based on the same logic: "large light-colored field areas paired with sparse grid-like ridge lines," with a note saying the output came from an analysis of tile colors and line density.
It added that the first two results broadly matched historical conditions, since the areas around present-day Xinyi District and Hsinchu Science Park were farmland in 1904. The third one did not. On the 1904 map for the Taipei Main Station area, the report said square urban blocks inside the city, dense building lines, and the word "Taipei" were clearly visible, indicating an urban built-up area rather than fields, even though the site gave that result the highest confidence score of the three at 54%.
The map itself may be more useful than the automated reading
BlockTempo said the most valuable part is the original material visible on the map itself. On the Taipei 101 view, users can still read old place names such as "Dajiazhen" and "Sanzhangli," names that now mostly survive only in bus stops. For the Hsinchu Science Park address, the returned administrative hierarchy still included names such as "Guandongqiao" and "Pingdingpu."
The report stressed that those details come from primary historical sources, not algorithmic guessing.
Kuo summed up his own experience this way: "I found that there was basically nothing where my home is now 100 years ago, and hardly anyone lived there. A bit disappointing." The report added that much of Taiwan in 1904 was still farmland or open land, and that what is rarer than discovering some dramatic past is finding that a place had already formed a village at the time.