WORLD NATURAL HERITAGE
On September 16, 2023, in Riyadh, Saudi Arabia, the 45th session of the UNESCO World Heritage Committee officially recognized the Ha Long Bay – Cat Ba Archipelago complex (located in Quang Ninh Province and Hai Phong City) as a World Natural Heritage Site.
Ha Long Bay and the Cat Ba Archipelago together represent an outstanding example of mature karst landscapes formed under hot and humid tropical conditions. The outstanding universal value of this heritage site lies in its drowned limestone karst terrain, characterized by majestic limestone towers and remarkable coastal erosion features such as arches and caves, which together create a truly spectacular natural landscape. In 1994, Ha Long Bay was inscribed by UNESCO as a World Natural Heritage Site, recognized for its exceptional aesthetic value. The landscape beauty and visual appeal of the Cat Ba Archipelago are not only comparable to Ha Long Bay but, in many aspects, surpass it in terms of diversity and pristine natural conditions. The drowned karst terrain in Cat Ba features hundreds of dramatic limestone towers (Phong Linh) and cones (Phong Tung), many of which are blanketed in primary tropical rainforest, rising from the emerald sea to form a majestic seascape similar to that of Ha Long Bay. hese islands remain in a near-pristine state, unmatched by any other place in the world. Therefore, the extension of the World Heritage Site to include the Cat Ba Archipelago, with its equally spectacular and harmonious beauty, serves to further strengthen the Outstanding Universal Value (OUV) of the property.
Steep terrain of Hon Dua area (Cat Ba)
Topographical Features
The large tropical limestone island of Cat Ba, along with hundreds of smaller surrounding islands in Lan Ha Bay (Cat Ba Archipelago) and the adjacent Ha Long Bay, together form a superlative coastal karst landscape, dominated by a matrix of dramatic limestone peaks and towers, many of which are steep-sided islands rising directly from the sea. The terrestrial portion of the Cat Ba Island World Heritage nomination area covers approximately 13,000 hectares, and is surrounded by about 20,000 hectares of coastal waters dotted with scattered islets. The island’s exceptional natural features have earned it recognition as a UNESCO Biosphere Reserve, covering a total area of 26,300 hectares. Elevation on Cat Ba Island ranges from 320–330 meters in the north, descending to about 250–260 meters in the south, with many deep valleys extending nearly to sea level—resulting in a landscape that is often steep and rugged. The larger offshore islands reach heights of 150–170 meters, while smaller islets can rise up to 100 meters. All of them are remarkable for their sudden and dramatic emergence from the sea, characterized by sheer limestone cliffs.
Northwest of the island
East – South Island
The Enigmatic Landscape of the Cat Ba Archipelago
Cat Ba adds a distinctive feature to the region: it is the largest island in the western South China Sea and, notably, a high island with wild, inaccessible nature in its interior. This is exemplified by rugged limestone peaks covered in forest, hidden inland lakes, narrow fjord-like bays carved deep into the coastline like a labyrinth, and islands with bizarre, mysterious shapes. The island’s interior landscape consists of mountain peaks interspersed with depression zones resembling the bottom of a bowl — often described as a giant egg tray draped in green forest. This honeycomb-like network of sunken basins, hidden beneath steep limestone cones, forms a remote habitat for Cat Ba Langurs and raptors, which are extremely difficult to access. Some of the lower-lying basins contain swamps and emerald-green lakes, the result of marine intrusion. Along the island’s coasts, other depressions, when opened through narrow passages or caves connected to the sea, form tidal inlets—small bays fringed by lush forests. The entire landscape feels otherworldly: precipitous cliffs sculpted by rainwater, jagged and steep, covered in lush monsoon rainforest, especially in shaded, secluded zones. There, you’ll find sharp limestone outcrops and needle-like karst peaks. A primal atmosphere permeates the interior, heightened by the chorus of frogs echoing after a heavy rain — nature at its most magical. For centuries, this picturesque landscape and the aesthetic charm of the dramatic limestone scenery have inspired traditional ink paintings of serene mountain-and-water landscapes (sơn thủy). The tropical island scenes have also been widely used in tourism and filmmaking. In this respect, the aesthetic value of Ha Long Bay, already recognized, has drawn significant international attention. The newly nominated area including Cat Ba Island is fully comparable in terms of scenic beauty and therefore serves as a complementary and equivalent justification for the World Heritage nomination.
Cat Ba archipelago seen from above
Island Village
Cat Ba National Park
The sharp peak of Cua Dong island where Cat Ba langurs live
Traditional Fishing Village Landscapes and Cultural Values
Small villages scattered along the coastline are connected by simple rural roads and footpaths. Some villages are tucked away in narrow sheltered bays, especially along the southern coast, and float directly on the sea. All of them reflect the traditional fishing lifestyle that has existed for centuries. These floating fishing villages, with their traditional fishing boats and colorful settings, significantly enhance the diversity and unique beauty of the landscape. They create a striking visual contrast against the backdrop of towering limestone cliffs. This iconic image was featured on the cover of the IUCN specialist study “Caves and Karst in World Heritage” (2008).
Trời, biển, đảo hòa quyện trên vịnh Lan Hạ, Cát Bà
The Indigenous Aesthetic Value of Cat Ba
At the heart of the Ha Long Bay – Cat Ba Archipelago lies a landscape of wild nature, largely untouched by human impact. Alongside it, the floating fishing villages with houseboats add a distinct and indigenous aesthetic element to the offshore scenery. The forests here are primary rainforests, echoing with the raw sounds of nature. The waters in the hidden lagoons are crystal-clear, with colors that change depending on their proximity to the sea and salinity levels—ranging from deep transparent green to milky blue. The pure air and the limestone terrain reflect a landscape shaped entirely by nature—where land and sea converge and constantly shift. The harmony of rock, water, forest, and sky creates a dynamic natural world of unparalleled beauty and allure. The multicolored landscape reflects the gray hues of mountain rock, the shades of green in the forest, and the gradual transition between the deep blue of the open sea, the aquamarine tones of hidden lagoons, and the secluded tidal lakes and narrow bays. One of the most remarkable features is the changing landscape when rain begins: the gray limestone instantly turns black, a result of cyanobacteria (blue-green algae) soaking in rainwater—transforming the scene into a palette of darker tones.
Primary forest on Cat Ba island
Fishing village on the bay
Saltwater lake
Panorama of Cat Ba
Caves and Grottos in Cat Ba
The hidden underground world of Cat Ba Island comprises a network of caves and streams that remain largely unexplored. While a few are open to tourists, many others remain untouched, preserving their natural, pristine state. These hidden places silently accumulate evidence of environmental changes over thousands of years, in the form of sediment layers and organic traces—natural records of past events from the world above.
Golden Fruit Cave Stalactite
Bright Cave
Trung Trang Cave
Stalactites of Thien Long Cave
Tower- and Cone-Shaped Limestone Island Landscapes in the Southeast of the Cat Ba Archipelago
All visitors to Lan Ha Bay (Cat Ba) and Ha Long Bay are left in awe by the sight of towering limestone pinnacles (Phong Linh) and cone-shaped hills (Phong Tung) that appear to float on the sea surface. Some are connected to forest-covered hills, with rugged cliffs accentuating the mystical beauty of Cat Ba Island. The natural experience here is deeply inspiring, yet it also demands a coordinated and effective effort to sustainably manage its values amid increasing visitor numbers. Therefore, the extension of Ha Long Bay’s World Natural Heritage to include the Cat Ba Archipelago, under Criterion (vii) (aesthetic value), is essential to ensure the long-term integrity of the Ha Long Bay – Cat Ba Archipelago.
