Hạ Long Bay is the most visited tourist spot in Vietnam due to its fascinating scene. The Bay has an area of 1,553 km2, including 2,000 islets, most of which are limestone. 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. Hạ Long Bay is home to 14 endemic floral species and 60 endemic faunal species.