The Cat Ba Archipelago is a group of islands located in Ha Long Bay, Vietnam. It consists of around 366 islands, with Cat Ba Island being the largest and most developed. The archipelago is known for its stunning limestone karsts, diverse ecosystems, and rich biodiversity, including rare species like the Cat Ba langur. The area is part of the Cat Ba National Park, which protects its unique flora and fauna. Visitors can enjoy activities such as hiking, kayaking, and exploring beautiful beaches. The archipelago is also a UNESCO World Heritage Site, recognized for its natural beauty and ecological significance.