Merak valley is located in eastern Bhutan within the Trashigang Dzongkhag (district). It is a unique valley inhabited by a semi-nomadic people known as the Brokpas. Situated at a height of 3000 meters, the valley remains untouched by the influence of the outside world.
Living close to nature in this pristine wilderness, the Brokpas way of life has remained virtually unchanged for thousands of years and they depend almost entirely on yak rearing and animal husbandry for their livelihoods. Bartering is still the main form of economic activity amongst the Brokpas. They barter their Yak products for food grains and other daily necessities with the neighbouring Tshanglas.
Their attire is also unique as it is entirely woven out of Yak hair and sheep wool. Their culture is also the only one of its kind in that they are one of the few communities to practice polyandry. In fact it is a common norm amongst the Brokpa women to marry all the brothers in a family. They are also fun loving and enjoy merry making with lots of festivities. Indeed, they love music and dance and attending Tshechus.
The Merak Tshechu is an annual three day event at the Merak Lhakhang and provides the Brokpas with some much needed respite from their daily cattle herding routine. Beside the dances that are performed throughout the Dzongs and Lhakhangs, the Brokpas also perform their traditional dances known as Ache Lhamo and the Yak dance. These rare dances are exclusive to the Brokpas and have drawn a lot of visitors to witness the unique spectacle.
Source: http://www.tourism.gov.bt/activities/merak-tshechu#sthash.I9wJDTND.dpuf