Vietnam (i/ˌviːətˈnɑːm/, /viˌɛt-/, /-ˈnæm/, /ˌvjɛt-/; Vietnamese pronunciation: [viət˨ naːm˧] ( listen)) officially the Socialist Republic of Vietnam (Cộng hòa Xã hội chủ nghĩa Việt Nam ( listen)), is the easternmost country on the Indochina Peninsula in Southeast Asia. With an estimated 90.3 million inhabitants as of 2012, it is the world's 13th-most-populous country, and the eighth-most-populous Asian country. The name Vietnam translates as "South Viet", and was officially adopted in 1945. The country is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea to the east. Its capital city has been Hanoi since the reunification of North and South Vietnam in 1976.
Ha Long Bay (Vietnamese: Vịnh Hạ Long, listen, literally: "descending dragon bay") is a UNESCO World Heritage Site, and a popular travel destination, located in Quang Ninh province, Vietnam. Administratively, the bay belongs to Hạ Long City, Cẩm Phả town, and part of Van Don district. The bay features thousands of limestone karsts and isles in various sizes and shapes. Ha Long Bay is a center of a larger zone which includes Bái Tử Long bay to the northeast, and Cát Bà islands to the southwest. These larger zones share similar geological, geographical, geomorphological, climate, and cultural characters.
Ha Long Bay has an area of around 1,553 km2, including 1,960–2,000 islets, most of which are limestone. The core of the bay has an area of 334 km2 with a high density of 775 islets. The limestone in this bay has gone through 500 million years of formation in different conditions and environments. The evolution of the karst in this bay has taken 20 million years under the impact of the tropical wet climate. The geo-diversity of the environment in the area has created biodiversity, including a tropical evergreen biosystem, oceanic and sea shore biosystem. Ha Long Bay is home to 14 endemic floral species and 60 endemic faunal species.