The westernmost point of Vietnam is the landmark at the intersection of the border lines of the three countries Vietnam - Laos - China (also known as the A Pa Chai landmark, the border crossroads, the 3-border landmark, the landmark number 0), coordinates 22° 24'02,295" North latitude - 102°8'38.109" East longitude, located on the top of Khoang La San, 1,866.23m high, belonging to Ta Mieu village, Sin Thau commune, Muong Nhe district, Dien Bien.