Gamaksan (Korean: 감악산), also known as Kamak Mountain or Hill 675 (675고지) during the Korean War, is a mountain in Gyeonggi Province, South Korea. Its sits between the cities of Paju, Yangju and Yeoncheon County. Gamaksan has an elevation of 675 m (2,215 ft).

It has been one of the sacred mountains of shamanism since the Silla dynasty. According to the Annals of King Taejo, during the Joseon dynasty, the royal court held a byeolgieun on this mountain in spring and autumn. In the middle of the mountain, there was Gamaksa Temple, now demolished. Since the Three Kingdoms period it has been a battleground: Battles were fought here during the Khitan invasion, and it was also the main battlefield of the Battle of Gorangpo during the Korean War. Being on the border of the demilitarised zone (DMZ) there continue to be military bases closeby.

• List of mountains in Korea

• Mossman, Billy C. (1990). "Map 34". Ebb and Flow : The United States Army in the Korean War : November 1950 - July 1951. Washington, D.C.: Center of Military History.
• Yu Jeong-yeol (2007). 한국의 산 여행 (Travel Guide to Korean Mountains). Seoul: 관동 상억연구회 (Kwandong). ISBN 978-89-958055-1-0.

37°56′30″N 126°58′08″E / 37.94167°N 126.96889°E / 37.94167; 126.96889