Cat Ba Archipelago located in Cat Hai island district, Hai Phong City is a population of 367 large and small limestone islands including Cat Ba Island in the southern part of Halong Bay, off the coast of Hai Phong and Quang Ninh Province, about 30 km from Hai Phong city center, 25 km from Halong city. The Cat Ba Archipelago has tropical rainforests on limestone islands, mangrove forests, coral reefs, seaweed and seagrass beds, cave systems. Cat Ba Archipelago has been recognized by UNESCO as a biosphere reserve in the world.

Cat Ba Island is the largest island of 1.969 islands in Halong Bay. Cat Ba is a beautiful and poetic island, located at an average height of 70m above sea level. Cat Ba Island has Cat Ba town in the southeast and 6 communes: Gia Luan, Hien Hao, Phu Long, Tran Chau, Viet Hai and Xuan Dam. On the main island of Cat Ba, there is a primeval forest on the limestone mountain, Lan Ha Bay in the southeast and 139 small silky sandy beaches with the clear blue sea water, no waves, which is suitable for swimming and relaxing. Cat Co beach (1,2,3), Tung Thu beach, Monkey Island beach are the most popular tourist beaches of Cat Ba Island. In addition, Cat Ba Island also has Cat Ba National Park, Viet Hai Village, Trung Trang cave, Quan Y cave, Cannon Fort, etc.

With the majestic and pristine beauty, Cat Ba is known as the jade of the Gulf of Tonkin.