Thimphu formerly spelled as Thimbu or Thimpu is the capital and largest city of the Kingdom of Bhutan. It is situated in the western central part of Bhutan, and the surrounding valley is one of Bhutan's dzongkhags, the Thimphu District. The ancient capital city of Punakha was replaced as capital by Thimphu in 1955, and in 1961 Thimphu was declared as the capital of the Kingdom of Bhutan by His Majesty the 3rd Druk Gyalpo Jigme Dorji Wangchuck. The city extends in a north-south direction on the west bank of the valley formed by the Raidak River, which is known as the Wang Chuu or Thimphu Chuu in Bhutan. Thimphu is the fourth highest capital in the world by altitude and ranges in altitude from 2,248 metres (7,375 feet) to 2,648 metres (8,688 feet). Unusually for a capital city, Thimphu does not have its own airport, but relies on the Paro Airport connected by road some 54 kilometres (34 miles) away. Thimphu contains most of the important political buildings in Bhutan, including the National Assembly of the newly-formed parliamentary democracy and Dechencholing Palace, the official residence of the King, located to the north of the city.