For decades, most residents of the Taiwanese capital simply thought they were lucky to have such a striking national park on their doorstep. Geologists knew about the Datun (sometimes spelt Tatun) Volcano Group, a body of around 20 peaks, in the park, but they largely thought that the fumaroles and hot springs were simply remnants of its fiery past. With no historical records of an eruption, the accepted view was that the group was extinct and no longer posed a risk.