Cat Ba National Park is 15 km to the North – West of the town. The Cat Ba National Park covers an area of 15,2 ha, including 9,8 ha of forests with splendid grottoes. In tropical and primeval forests, there is a rich fauna and flora. There are 745 species of plants, including various species of rare wood trees so as Tri Ly, Lat Hoa, Lim Set, Gie Hoa, Kim Giao, white wood. Kim Giao chopsticks used to be offered to Kings which can cause bubbles and turn itself into red when touched poisoned food. Cho dai tree that can be found in the old forest is endangered specie named in the Red Book, the only other in the world where we can find this tree is Hymalaya mountain.
Cat Ba National Park is home to 2 species of mammals, 69 species of birds, 2 species of reptiles and species of amphibians, species of 11 frogs. Particularly, the rarest animals in the world that can only be found in Viet Nam is Vooc (white faced monkeys). Another strange is Ma Tien fruit, a toxic fruit, if a person eats Ma Tien he will die immediately, but the white-faced Vooc can eat both leaf and fruit to feed them.