[Report] In Front of the 10,000-Year Mystery, We All Put Down Our Flashlights

Jeju Volcanic Island Lava Caves (Bengdugul, Manjanggul, Gimnyeonggul) Report
26km Cave Formed by Lava Flow 10,000 Years Ago
Narrow and Rugged Caves Restricted to Public, Accessible During Jeju World Natural Heritage Festival
Crawling Through Pitch-Dark Darkness, Thrilling Cave Passage
Served as Shelter for Residents During Jeju 4·3 Incident

Reporters visiting Bengduigul located in Seonheul-ri, Jocheon-eup, Jeju-si, Jeju-do, looking outside the cave. Bengduigul, a natural monument, is the most complex cave in Korea and shows characteristics of the early stages of cave formation, making it highly valued worldwide. Photo by Kim Heeyoon

[Jeju=Asia Economy Reporter Kim Heeyoon] "Please turn off your flashlights and headlamps for a moment."

On the 25th of last month, at ‘Bengdugul’ in Jocheon-eup, Jeju Island, everyone held their breath in front of the cave, a World Natural Heritage site preserving the mysteries of primordial times. At the suggestion of curator Ki Jinseok, who was guiding the cave tour, all brought lights were turned off.

At that moment, a dreamlike event occurred. A pitch-black darkness came, making it impossible to tell whether one’s eyes were open or closed. It was the first time experiencing complete darkness since birth. Was it a ritual guiding into an unknown world? Bengdugul, known to have formed 10,000 years ago, captivated the explorers’ eyes and ears with its ancient mysteries preserved in its original state.

It was a complex feeling of excitement and reverence. Human time and natural time are both the same and different. One hour, one day, one month, one year... what feels long to humans might be just a fleeting moment before nature.

When the shared time of darkness ended, flashlights were turned on one by one. Crawling on hands and knees, they passed through the middle part of the cave. Traces of flowing lava and paths of fire remained throughout the cave, creating a precarious and dizzying atmosphere. That space, untouched by human hands, would have exposed visitors to injury risks without helmets and work clothes.

Experiencing the 10,000-year mystery demands a price. Moving through slippery, uneven lava rocks on the floor, they practically crawled. However, the passion of prostration offered to nature bore fruits that could not be exchanged for anything. The experience of facing the inner depths of Bengdugul after passing the rugged ground and lava walls was an exciting moment filled with exclamations.

Bengdugul is a lava cave formed 10,000 years ago. It is one of the UNESCO World Natural Heritage sites under ‘Jeju Volcanic Island and Lava Tubes.’ It is located at the upper part of the 26 km-long ‘Trail of Fire,’ where lava flowed from Geomunoreum to Woljeongri coast.

The internal structure of Bengdugul, where the movement of lava flowing over flat land can be observed. Although access is restricted to the general public, visitors are temporarily allowed during the Jeju World Natural Heritage Festival. Photo by Kim Heeyoon

The cave, named Bengdu after the Jeju dialect word for a wide field, is known as the largest maze-type lava cave in Korea, where lava flowed over flat land and branched out like a spider web. The total length is 4.5 km, with more than ten entrances, and its complex interior structure that does not let light escape made it a shelter for residents fleeing from the suppression forces during the Jeju 4·3 Incident.

A space that protected the lives of people who escaped the chaos of history. Bengdugul holds a special meaning for the people of Jeju Island.

"Some household tools used by residents at that time remain inside the cave," curator Ki explained, and everyone listened attentively. Although the breath of that time could not be felt, the space that once allowed human rest felt special.

Bengdugul was off-limits to the general public for a while due to its narrow and rugged structure and the value of its cave ecosystem formed over thousands of years. However, this year, access to the space was allowed to a limited number of people for a special reason.

During the third Jeju World Natural Heritage Festival period (October 1?16), limited exploration was permitted only to a special expedition team.

The Geomunoreum Lava Tube System, which includes Bengdugul, refers to a group of lava caves formed as lava flows erupted multiple times from Geomunoreum flowed along the terrain’s slope about 14 km to the coast. Geomunoreum, meaning ‘sacred place,’ was recognized as a natural heritage of exceptional value by UNESCO surveyors who said, "It feels sacred, so it is not right to enter further," acknowledging its value by its exterior alone.

The appearance of stalactites like jewels formed on the ceiling of Bengdugul Cave in Jeju. When illuminated, they sparkle like gold dust, composed of fungi inhabiting the humid cave environment. Photo by Kim Heeyoon

Before exploring Bengdugul, the team visited Manjanggul, the largest cave in the Geomunoreum Lava Tube System, with a total length of 7.4 km, a maximum width of 18 m, and a maximum height of 25 m. There are three entrances in total, but currently only a 1 km section from the second entrance is open to general tourists.

Entering the unpublished section of the first half of the second entrance, the upper and lower double structure was clearly visible, with rope-like wrinkle layers on the floor formed by lava, giving a sense of the scale and direction of the lava cave that flowed here 10,000 years ago. Large stalactites and various shaped stones overwhelmed visitors with their scale.

Next, they visited Kimnyeonggul, located in section 4 of the ‘Trail of Fire,’ where the white sand on the floor was impressive. Passing through sand blown and accumulated from the sea, a 705 m-long cave appeared. Due to safety concerns from falling rocks, this area is currently off-limits, but limited exploration was allowed during the festival period.

Hosted by the Cultural Heritage Administration and Jeju Special Self-Governing Province, and organized by the Korea Cultural Heritage Foundation and the World Natural Heritage Village Preservation Association, this festival will be held from October 1 to 16 across the World Natural Heritage sites in Jeju. This year’s festival includes experiential programs such as the ‘World Natural Heritage Walking Tour,’ which walks the entire lava trail, and the ‘Special Expedition Team,’ which explores unpublished areas of Bengdugul and Manjanggul.

On October 15, a commemorative ceremony open to all will be held at the special stage at Seongsan Ilchulbong. As the world’s only festival centered on world natural heritage, the Jeju Natural Heritage Festival is highly rare globally. Kang Kyungmo, the general director overseeing the festival, emphasized, "The Jeju Natural Heritage Festival is a special opportunity to encounter Jeju’s natural heritage with outstanding academic and natural heritage value," adding, "This year, the seven World Natural Heritage villages (Seonheul 1-ri, Seonheul 2-ri, Deokcheon-ri, Woljeong-ri, Kimnyeong-ri, Haengwon-ri, Seongsan-ri) are directly managing the festival, which has deepened the program’s quality."