Ba Mun Island is an island belonging to Minh Chau communes of Van Don District of Halong Bay, lying parallel to the island of Quan Lan. The Island is also known as High Island Block. Ba Mun Island is about 15 km from the shore. The island has an area of approximately 1800 hectares with more than 20 km in length, narrow width, stretching from east to west. The highest mountain is called Mandarin mount (Quit mountain), with a height of 397 m. The flora and fauna on the island is very rich and there are many rare species. Ba Mun has several rare species of animals, including the golden deer, which is still quite populous and the only population in northeast Vietnam. Golden deer often search for food at night. Therefore, it is hard to spot them during the day but visitors can see their footprints.
Ba Mun Island is the only schist island with primeval forests in Halong Bay. On the island there are numerous rare types of timber. Some of them include Dinh timber, Lim timber, Sen Timber, Tau Timber. They are all trees standing there for many years, developing a huge circumference. Some grow so big that they require three to four people to hug around. Ba Mun Island is where many species of rare animals such as antelope, deer, monkeys, langurs and sea birds, migratory birds … are being protected. On 01/24/1997 Ba Mun forest has been recognized as Bai Tu Long national Forest.