Thousands of caves riddle the limestone plateau, most never mapped. Recent expeditions discovered endemic blind fish and cave-adapted invertebrates found nowhere else on Earth.
A Landscape Carved from Ancient Seabeds
The Shan Plateau, an immense highland region covering over 63,000 square kilometers, is defined by its geology. Much of this vast expanse is composed of a thick layer of carbonate rock, primarily Permian-Triassic limestone and dolomite, in some places reaching a thickness of more than 2,000 meters. This "Plateau Limestone" formed from the compressed remains of marine life on ancient sea floors hundreds of millions of years ago.
Over eons, the region's warm, rainy climate and complex tectonic history have created a classic karst topography. Rainwater, made slightly acidic by atmospheric carbon dioxide, has relentlessly dissolved the soluble limestone, carving out a subterranean world of sinkholes, underground rivers, and extensive cave systems. This process has created a highly fragmented, island-like habitat of isolated caves and karst hills. This separation drives evolution, leading to high levels of site-specific endemism. The Myanmar Cave Documentation Project, which began systematic exploration in 2009, has so far recorded over 600 individual karst features and surveyed 37 kilometers of cave passages, yet this is only a small part of what lies beneath.
Life in Perpetual Darkness
The absolute darkness of the Shan caves forces life to adapt in extraordinary ways. These ecosystems, devoid of light for photosynthesis, rely on nutrients brought in from the outside world, primarily by subterranean streams and bat colonies. The animals that live their entire lives in this environment, known as troglobites, exhibit evolutionary changes. Common adaptations include the complete loss of eyes and pigmentation, which are useless in the dark, and the development of elongated appendages and heightened non-visual senses for navigation and hunting.
Recent expeditions have begun to catalog this unique biodiversity. The 2013 Shan Plateau Expedition collected the first known specimens of cave-adapted fish in Myanmar. Subsequent research has formally identified new genera and species, such as Kayahschistura lokalayensis, a loach from Kayah State distinguished by its lack of color and highly regressed eyes. Beyond fish, scientists have documented a host of other endemic troglobites. Expeditions have collected specimens of at least 62 different taxa, including large huntsman spiders of the genus Heteropoda and various species of cave crickets. Researchers have also identified new species of cave geckos and scorpions, including one scorpion from a different region of Myanmar with a unique trichobothrial (sensory hair) pattern unknown elsewhere in its family. Each isolated cave system is an evolutionary island, potentially harboring species found nowhere else on earth.
💡Fun Facts
The limestone that forms the plateau is primarily from the Carboniferous to Lower Triassic periods, making the rock itself between roughly 252 and 359 million years old.
The longest surveyed cave system in the region, Som Hein, was mapped to a length of 11.6 kilometers in 2020 and is still being explored.
The cave ecosystems are heavily dependent on the guano (droppings) from fruit and insectivorous bats, which forms the base of the food web for many detritivores (debris-eaters).
Some caves on the plateau, like the famous Padalin Caves, contain evidence of human occupation dating back 12,000 years, including charcoal remains and prehistoric paintings.
The specific cave locations for scientific discovery are not public. Access is by scientific permit and specialized expedition only.
Admission
N/A
Accessibility
Access to unexplored caves is extremely difficult, requiring vertical caving equipment, extensive safety knowledge, and permission from local authorities. Many sites are remote and have no established paths.