Ao Coi Otter Valley is a real aosis located in Catba nutural park, surrounded by mangrove forests and Phu Long river. From here we will have chances to explorer the untouched nature of Cat Ba with Thien Long cave and submerged mangrove forests . We offer kayaking, boating and trekking trips to really get off the beaten tracks like no Other in Catba archipelago that go beyond the ordinary. Please drop us a message on WhatsApp: + 84 912 555 208 for further informations