Seolmacheon (Korean: 설마천) is a stream in South Korea. It is a tributary of the Imjin River, which it joins at Jeokseong. It was on Gloster Hill, between the two rivers, that the British Gloucestershire Regiment made their last stand against the Chinese in the Battle of the Imjin River, a major event in the Korean War, from 22–25 April 1951. At the Gloucester Valley Battle Monument the British Embassy in Seoul organises a service every April in commemoration.