Located within the UNESCO Dak Nong Global Geopark, the cave system is among the most distinctive geological features of Vietnam's Central Highlands.
The geopark covers approximately 4,760 square kilometres across 22 communes and wards in western Lam Dong Province, encompassing volcanic landscapes, basalt plateaus and prehistoric archaeological sites.
Geological and archaeological significance
Scientific studies indicate that volcanic activity over the past 16.5 million years shaped the geopark's basalt plateaus, craters, lava flows and extensive cave networks.
The Nam Blang-Chu B'Luk volcanic cave system in the Krong No area is a major highlight.
Discovered in 2007, the area has since been surveyed by Vietnamese and international researchers, who have identified nearly 50 basalt caves with a combined surveyed length exceeding 10 kilometres.
It is considered one of Southeast Asia's most extensive and distinctive volcanic cave systems.
The caves formed when the outer layers of flowing lava cooled and hardened while molten lava continued moving beneath them, leaving hollow tunnels.
Many retain geological features such as lava formations, secondary tubes and gas vents, providing evidence of ancient volcanic activity.
C7 Cave is particularly notable. Scientists have identified it as Southeast Asia's longest volcanic cave, measuring approximately 1,266 metres following the discovery and mapping of additional passages in 2022.
Beyond their geological importance, the caves contain archaeological evidence of prehistoric human activity dating back 6,000-7,000 years.
Researchers have uncovered traces of habitation, toolmaking and burials, offering insights into how prehistoric communities adapted to volcanic environments.
Nguyen Tri Quang, Vice Chairman of the Nam Da Commune People's Committee, said protecting the geopark and its caves was a local priority.
Authorities are strengthening heritage management and regulating tourist access, while warning visitors against entering dangerous caves without authorised guides.
Balancing conservation and tourism
In late October, the Ministry of Culture, Sports and Tourism designated A1 and C2 caves in Nam Da Commune as national scenic monuments, recognising their geological and tourism significance.
A1 Cave, also known as Bat Cave or Honeycomb Cave, is located in Buon Choah Hamlet.
Measuring 438.7 metres long and lying approximately 8-10 metres below ground, it features distinctive lava formations and honeycomb-like cavities, sometimes described as "devil's eyes".
C2 Cave, also known as Crocodile Cave, lies in Duc Lap Hamlet at an elevation of approximately 393-395 metres.
It contains unusual geological formations, including a crocodile-shaped lava structure, a bow-like formation where two lava flows converged and V-shaped lava channels.
Scientists consider these features valuable for geological research and education.
The caves offer potential for geological exploration, adventure tourism and educational visits, but experts warn that uncontrolled access could cause irreversible damage.
Tran Tan Van, Chairman of the Vietnam UNESCO Global Geoparks Network, said lava caves were particularly sensitive environments.
Unauthorised entry, littering, illegal sample collection and disturbance of archaeological deposits could damage geological structures, ecosystems and cultural remains.
He recommended geological and safety assessments, strict protection zones, visitor limits and controlled routes before expanding tourism activities.
Meanwhile, Lam Dong is preparing for the UNESCO Dak Nong Global Geopark's scheduled revalidation assessment in July 2027.
Provincial authorities are implementing seven groups of UNESCO recommendations, focusing on heritage protection, scientific research, infrastructure improvements and geotourism development.
The province aims to preserve the caves' geological and archaeological features while developing carefully managed tourism to support economic growth in western Lam Dong.