ShotHotspot has mapped 13 abandoned places in Taiwan, ranked by how often they're photographed, viewed and voted for. The most popular are 廣天宮櫻花 百果山 員林百果山風景區, 虎頭山遠眺埔里盆地 and Corridor Taichung Urban Abandoned. Some are private property or unsafe, so get permission before you visit.
We don't know whether you're allowed to visit any of these places. Many are private property, closed to the public or unsafe: get permission from the owner or the relevant authority, and take safety precautions.
ShotHotspot is a search engine for photography locations: it maps where people take photos, worldwide, from millions of geotagged photos. Browse by country, abandoned places, guides.