Tham Luang Nang Non (, , ), also known as Tham Luang or Tham Yai, is a

karstic Karst () is a topography formed from the dissolution of soluble carbonate rocks such as limestone and dolomite. It is characterized by features like poljes above and drainage systems with sinkholes and caves underground. There is some eviden ...

cave system in the Tham Luang–Khun Nam Nang Non Forest Park, near the village of Ban Chong in Pong Pha subdistrict, in

northern Thailand Northern Thailand, or more specifically Lanna, is a region of Thailand. It is geographically characterized by several mountain ranges, which continue from the Shan Hills in bordering Myanmar to Laos, and the river valleys that cut through them. ...

. It lies beneath Doi Nang Non, a mountain range on the border with Myanmar. Initially just known to locals, Tham Luang Cave gained to international fame during a significant rescue mission on July 2, 2018. The cave was brought to international prominence when twelve members of a junior

association football Association football, more commonly known as football or soccer, is a team sport played between two teams of 11 Football player, players who almost exclusively use their feet to propel a Ball (association football), ball around a rectangular f ...

team and their assistant coach were found deep inside the cave. They had become trapped due to

monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in Atmosphere of Earth, atmospheric circulation and precipitation associated with annu ...

al flooding on June 23. A rescue effort succeeded in bringing them out safely by July 10. Two Thai rescue divers died as a result of the rescue. Tham Luang is the fourth largest cave in Thailand, stretching through a series of winding halls, low ceilings, rock collapses, and deep recesses with

stalactites A stalactite (, ; , ) is a mineral formation that hangs from the ceiling of caves, hot springs, or man-made structures such as bridges and mines. Any material that is soluble and that can be deposited as a colloid, or is in suspension, or is ca ...

, stalagmites, and reflective stone surfaces. It is open to guided tours from November to April, though many parts remain inaccessible.

Geography

Tham Luang Nang Non is a prominent cave system located in Mae Sai District, Chiang Rai Province, Thailand. Situated under the Doi Nang Non mountain range, this natural landmark forms part of the border between Thailand and Myanmar. The cave, which extends for approximately 10.3 kilometers (6.4 miles), is the fourth largest in Thailand and features a complex layout of twisting paths, narrow passages, and expansive chambers. The entrance of the cave is at an altitude of 446 meters above sea level, while the mountain itself rises to a peak of 1,389 meters. The terrain of the cave system includes flooded tunnels, rocky elevations, and maze-like corridors, making navigation challenging. The cave is shaped by the interplay of

granite Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...

and

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

formations, with the west side of the mountain prominently showcasing where these geological elements converge. Above the cave, the Doi Nang Non mountain range, often shrouded in clouds, is rich with vegetation.

Teak Teak (''Tectona grandis'') is a tropical hardwood tree species in the family Lamiaceae. It is a large, deciduous tree that occurs in mixed hardwood forests. ''Tectona grandis'' has small, fragrant white flowers arranged in dense clusters (panic ...

, Burma padauk, and bamboo trees line the streams flowing through the surrounding forest, creating a cool and shaded environment. The mountain's silhouette resembles a reclining woman, giving the cave its name, which translates to "the big cave and water source of the sleeping lady mountain." Tham Luang is known for its striking rock formations, including

and stalagmites, and its distinctive water-formed features created by millennia of groundwater erosion. This natural wonder is both an ecological treasure and a testament to the region's complex karst landscape. A visitor center outside the main entrance provides a detailed map of the cave, and there is a car park nearby. The first 1 kilometer (0.6 mi) of the cave is open to the public for guided tours between November and April. However, the cave floods during the rainy season and is closed to visitors during that time. This makes Tham Luang a popular destination during the dry season while preserving its natural state during the

Climate

Tham Luang Nang Non is a

seasonal A season is a division of the year based on changes in weather, ecology, and the number of daylight hours in a given region. On Earth, seasons are the result of the axial parallelism of Earth's axial tilt, tilted orbit around the Sun. In temperat ...

cave system significantly impacted by the regional climate. The cave is open for exploration during the dry months, typically from November to April. However, the rainy season, starting in July, brings heavy

rains that make the cave unsafe for visitors. During this period, rainwater from the Doi Nang Non mountain range floods the cave system, with water levels rising up to 5 meters in some areas. This influx of water fills the interconnected tunnels and chambers, making navigation impossible. The saturated mountain channels water directly into the cave system, further contributing to the flooding. To ensure safety, authorities close the cave during the rainy season. Visitors are advised to plan trips during the dry season when conditions are more stable.

Fauna

Tham Luang Nang Non is home to a delicate

ecosystem An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...

that includes numerous

endemic species Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

, many of which cannot be found elsewhere. The cave's unique environment supports diverse fauna, including various

bats Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

invertebrates Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordate subphylum ...

, and

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

that thrive in its permanent streams. Environmentalists caution against drastic changes to the cave, as even minor disturbances can lead to irreversible damage and the potential extinction of these specialized species, highlighting the need for careful conservation efforts in this fragile habitat.

History

The cave system is situated beneath the Doi Nang Non-Mountain range, which translates to "Mountain of the Sleeping Lady." This name is derived from local legends that tell of a beautiful princess who fell in love with a

commoner A commoner, also known as the ''common man'', ''commoners'', the ''common people'' or the ''masses'', was in earlier use an ordinary person in a community or nation who did not have any significant social status, especially a member of neither ...

. According to one version of the tale, after fleeing from her father's wrath, she took refuge in the cave. Tragically, her lover was killed by soldiers sent by her father, leading her to take her own life. Her blood is said to have formed the Mae Sai River, while her body became the mountain itself. This legend has deep cultural significance for the local Tai Yai ethnic group and reflects their spiritual connection to the land and its natural features

1986 Protected Area

In 1986, a portion of the Doi Nang Non range was designated as Tham Luang–Khun Nam Nang Non-Forest Park. This designation aimed to protect the unique

karst Karst () is a topography formed from the dissolution of soluble carbonate rocks such as limestone and Dolomite (rock), dolomite. It is characterized by features like poljes above and drainage systems with sinkholes and caves underground. Ther ...

landscape and its biodiversity while promoting sustainable tourism. Despite its natural beauty and ecological importance, the area remained relatively unknown to tourists until a significant event in 2018 brought it international attention.

2018 Cave Rescue

In 2018, twelve boys aged 11 to 16, all members of a junior

team, and their 25-year-old male assistant coach were stranded in the cave for 18 days by a flood. They were rescued in a massive joint operation between the Thai government, the Thai military, and a group of international expert cave divers. British divers found them on a muddy ledge in darkness more than from the entrance nine days into their ordeal. The effort to save their lives was a global operation watched around the world. In all, 90 divers – 50 of whom were foreigners – helped to extract the group. An ex-navy diver, Saman Kunan, died during the mission because he ran out of air, having placed air tanks along the route for the boys. Another diver and ex-Navy Seal, Beirut Pakbara, died the next year from a

septic shock Septic shock is a potentially fatal medical condition that occurs when sepsis, which is organ injury or damage in response to infection, leads to dangerously low blood pressure and abnormalities in cellular metabolism. The Third International C ...

from an unspecified

blood infection Bloodstream infections (BSIs) are infections of blood caused by blood-borne pathogens. The detection of microbes in the blood (most commonly accomplished by blood cultures) is always abnormal. A bloodstream infection is different from sepsis, w ...

he contracted during the cave rescue.