At 2,565 metres above sea level, Doi Inthanon stands as Thailand's highest point, a granite massif crowned by montane evergreen forest and named for King Inthawichayanon, the last sovereign of Chiang Mai, who recognized its ecological importance in 1897. The king requested his ashes be interred here to protect the watershed that feeds the Ping River basin, and royal patronage transformed the mountain into a 482-square-kilometre national park in 1972. Twin pagodas built in 1987 and 1992 to honour King Bhumibol and Queen Sirikit anchor the summit plateau, their purple and maroon tiles refracting monsoon light across rhododendron thickets and sphagnum bogs found nowhere else in Southeast Asia. The park shelters 362 bird species, including the green-tailed sunbird and the Hume's pheasant, both endemic to montane zones above 1,800 metres. Seven Karen and Hmong villages occupy the lower slopes, their terraced vegetable plots and arabica coffee groves woven into reforestation programs initiated in the 1980s to replace opium cultivation. Wachirathan Falls plunges 80 metres over a basalt ledge near kilometre marker 21, its spray visible from the highway, while the Kew Mae Pan nature trail loops 3 kilometres through dwarf bamboo and oak forest, passable only with a park-appointed guide between June and October when the monsoon renders the ridge too hazardous for unsupervised hikers. Doi Inthanon National Park tour experiences range from dawn summit drives timed to catch the sea of mist at 06:30 to multi-day treks linking the Pha Dok Siew waterfall with overnight stays in hill-tribe homestays. The royal agricultural station at kilometre marker 12.5 cultivates temperate-zone crops — strawberries, persimmons, and Fuji apples — in demonstration plots open to visitors, a living laboratory of the late king's sufficiency economy principles. Winter temperatures drop to 5°C at the summit between December and February, requiring layered clothing even as the Chiang Mai valley below swelters at 28°C. The conservation fee of 300 THB per foreign adult sustains trail maintenance, wildlife monitoring, and community development funds distributed to the seven villages within park boundaries, ensuring that tourism revenue circulates through the same highland communities whose traditional land-use practices the park was created to regulate.