When Taiwan’s first and second nuclear power plants were constructed in the 1970s, the Shanjiao Fault (山腳斷層) of the Taipei Basin (台北盆地) was mistakenly believed to be dormant. However, it was recently confirmed that the fault has been active within the last 11,000 years and so it was reclassified as a Class II active fault. Also, it extends over a greater distance than was previously thought.