Doi Inthanon is Thailand's highest mountain at 2,595 metres. It is named after Phra Inthawichayanon, the last King of Chiang Mai, who died at the turn of the century, and whose remains lie interred in a small white chedi near the summit. Near the summit stand two remarkable chedis. The first is the copper-coloured spire of Phra Mahathat Chedi Nabhamethanidon, built by the Royal Thai Air Force to commemorate the 60th birthday of King Bhumibol, and inaugurated on December 5, 1987. Close by, but clad in lilac-purple rather than copper, stands the less massive, but more elegant spire of Phra Mahathat Chedi Nabhabolbhumisiri, similarly built by the air force to commemorate the 60th birthday of Queen Sirikit, and inaugurated on August 12, 1992.