The terrain of the northern mountains, full of complexity. The key areas of the country, many areas such as the western end of the district, Mae. Mae Hong Son province The northern end of the district of Sai. Chiang Rai province At the peak of Doi Inthanon. The northern province of Chiang Mai is also the first area of the river flow. The first point of the river flowing through the Golden Triangle area of Thailand. Chiang Saen Chiang Rai province