The "righteous army" (義兵) guerrilla forces who rose up in 1896 considered Namhan Mountain Fortress to be their base of operations. The 1,600 or so soldiers who gathered there consisted of units from Gwangju, Icheon and Yanggeun. They intended to join guerrilla bands from the three southern regions (Gyeongsang, Jeolla and Chungcheon), advance on the capital to chase out the Japanese troops stationed there, and reinstate Gojong as Emperor.
Their plans were thwarted, however, the Japanese authorities knew that Namhan Mountain Fortress was a hotbed of resistance. Therefore, Japanese troops removed all the weapons there in 1907, blowing up the gunpowder found on the site, burning all the temples down, and destroying many of the other structures. Yet, the fortress continued to be a staging area for resistance operations during the Japanese Colonial Period, including the March 1st Independence Movement in 1919.