The historical site of Hangpaduri is where the Sambyeolcho military unit of the Goryeo Dynasty resisted the invasion of Mongolia until the last possible moment. The site houses an exhibition hall, a monument, and a unique mud fortress. Nearby is Jangsumul Spring (Jangsu means general) which flowed from the footprints of General Kim Tong-jeong. Today, water from the spring cannot be used as drinking water. Sambyeolcho was a military unit of the Goryeo Dynasty. When the Goryeo Dynasty made peace with the Mongolian forces in February 1270 (the 11th year of King Wonjong), the Sambyeolcho special defense unit opposed it and launched a resistance movement. They moved their base to Jindo in Jeollanam-do but after suffering a huge defeat, they moved to Jeju-do and built Hangpaduseong Fortress. They continued to fight against the Mongolian forces for two more years there. However, all the members were killed in April 1273 (the 14th year of King Wonjong). This independent anti-Mongolian movement was born out the deeply patriotic belief in the need to safeguard the nation from foreign invasion. In 1977, the government invested 745 million won to restore part of the fortress and build a monument in commemoration of those who died in the war. The work was completed in June 1978.