Yen Bai is a province located in Tay Bac, the northern part of northern-central Vietnam. It shares borders with six provinces which are Ha  Giang province, La o Cai province, Lai Chau province, Son La province, Phu Thu province, and Tuyen Quang province. The province covers an areaof 6887.46 square kilometres and as of 2019 it had apopulation of 821,030 people.

The terraced fields in Mu Cang Chai. Mu Cang Chai is a rural district of Yen Bai Province, in the Northeast region of Vietnam. As of 2003, the district had apopulation of 42,574. The district covers an areaof 1,199 km2. The district capital lies at Mu Cang Chai.

Cam Duong cave (Hang Cam Duong) is the nicest cave in Yen Bai, located in the middle of the Bach Ngoc mountain in Chinh Quan village, Lieu Do commune, Luc Yen district, the Cam Duong cave can accommodate thousands of people. The cave’s mouth is 25m wide and stands at 12m high.