Bumthang District is one of the 20 dzongkhag (districts) comprising Bhutan. It is the most historic dzongkhag if the number of ancient temples and sacred sites is counted. Bumthang consists of the four mountain valleys of Ura, Chumey, Tang and Choekhor ("Bumthang"), although occasionally the entire district is referred to as Bumthang valley.
"Bumthang" directly translates as "beautiful field" – "thang" means field or flat place, and "bum" is said be an abbreviation of either "bumpa" (a vessel for holy water, thus describing the shape and nature of the valley), or simply "bum" ("girl," indicating this is the valley of beautiful girls).
Information based on http://en.wikipedia.org/wiki/Bumthang_District