Fill in each gap with one word from the box area impact around bay climate sizes prehistorical found including years geology cultures ago center share events Ha Long Bay is a UNESCO World Heritage site located in Quang Ninh province, Vietnam. The (1)______________ has thousands of limestone karsts (or limestone caves) and isles in various (2)______________ and shapes. Ha Long Bay is a (3)______________ of a larger zone which includes Bai Tu Long bay to the northeast, and Cat Ba islands to the Southwest. These larger zones (4)______________ similar geological, geographical, (5)______________ and cultural characters. Ha Long Bay has an area of (6)______________ 1,553 km 2 , including 1,960 islets, most of which are limestone. The core of the bay has an (7)______________of 334 km 2 with a high density of 775 islets. The limestone in this bay has gone through 500 million (8)______________ of formation in different conditions and environment. The evolution of the karst in this bay has taken 20 million years under the (9)______________ of the tropical wet climate. The diversity of the environment, climate, (10)______________ and geography in the area have created biodiversity, (11)______________ tropical evergreen biosystem, oceanic and seashore biosystem. Ha Long Bay is home to 14 endemic floral species and 60 endemic faunal species. Historical research surveys show the presence of (12)______________ human beings in this area ten of thousands years ago. The successive ancient (13)______________ are the Soi Nhu Culture around 18,000-7,000 BC, the Cai Bo Culture 7,000-5,000 BC and Ha Long Culture 3,500-5,000 years (14)______________. Ha Long Bay also marked important (15)______________ in the history of Vietnam with many artifacts (16)______________ in Bai Tho Mount, Dau Go Cave, etc.