Located in heart of the enchanting Dumchoe village, the monastery was initially established in the mid-7th century by King Songtsen Gampo in his mission to build 108 monasteries in one day. It is situated right north of Lhakhang Karpo. Legend holds that King Songtsen Gampo released a black and a white pigeon to select sites to build the temples. The black pigeon landed a little north of the white pigeon, indicating the preordained site of the present Lhakhang Nagpo. The temple was named Nagpo (black) as it was built on the site where the black pigeon landed.
As the Lhakhang Nagpo is built on a lake, the opening on the floor of the temple serves as the channel to the underground lake. Lhakhang Nagpo serves as the seat for the guardian deity Da Do Chen. The principal relic of the monastery is the Choe-Lung-truel Sum.