Burning Mountain: Australia’s Eternal Fire Beneath the Earth

Burning Mountain: A Fire Through the Ages

In a quiet corner of New South Wales, Australia, a hill perpetually smolders from within. What looks like an unassuming rise in the landscape hides a remarkable secret beneath its surface: a coal seam burning continuously for millennia. Wisps of sulfurous smoke curl from fissures in the ground, and the earth underfoot grows warm – hints of an ancient fire that refuses to die. This is Burning Mountain, known to the local Wanaruah people as Wingen, meaning "fire".

From Lush Permian Swamp to Coal Seam

To understand Burning Mountain’s origin, we must travel back nearly 250 million years, into the late Permian period. At that time, this region was not dry bushland but a vast swampy forest at the edge of an ancient coastline. Great rivers once coursed here, depositing silt and sand into a lush delta. Towering tree ferns, primitive pines, and giant horsetail plants thrived in the waterlogged earth, living and dying in endless cycles. Over countless generations, their thick layers of dead plant matter were buried in mud and lacking oxygen – slowly compressing into peat and, with deeper burial and time, transforming into coal. By the end of the Permian, a seam of coal several meters thick lay entombed under sediments, the preserved bounty of that primeval swamp.

Deep Forces Shape the Land

The Earth did not remain still after the Permian. Over the tens of millions of years that followed, tectonic forces gently folded and uplifted the strata in this region. Layers of rock that once lay flat were tilted and raised as Australia’s landmass shifted. In the Upper Hunter Valley, younger rock layers that had blanketed the area – sands and clays from the Triassic period above – were gradually worn away by erosion. Wind, rain, and time chiseled the landscape, exposing the ancient Permian coal bed that had been buried deep underground. What was once a subterranean secret eventually reached the surface in places, peeking out of hillsides and creek banks as dark outcrops of coal. By the time humans first walked these lands, the coal seam at Mount Wingen lay close enough to the open air that only a thin cover of soil and rock kept it hidden. The stage was set for an extraordinary ignition.

Igniting an Eternal Flame

No one knows exactly when the fire in Burning Mountain began – it started long before any written record, perhaps thousands or even tens of thousands of years ago. And how does a mountain catch fire? Scientists have pondered this mystery, and several theories have emerged. One possibility is a lightning strike or bushfire in ages past: a stroke of lightning or a wildfire could have ignited an exposed piece of the coal seam, starting a fire that never fully died out. Another theory suggests spontaneous combustion deep underground. The coal here is laced with minerals like iron pyrite (fool’s gold), which can oxidize and produce heat; perhaps in a dry spell the seam slowly heated itself to the point of ignition. With oxygen seeping in from cracks at the surface, a slow burn could have taken hold. Whatever the spark, by the time the Wanaruah people knew this place as Wingen, the underworld fire was already alive – a hot ember buried in the earth, quietly feeding on the coal of the mountain.

Once lit, the fire would have smoldered steadily onward. This is not a raging inferno with towering flames, but a subterranean ember that creeps through the coal seam. There were likely times it dwindled, starved of air or fuel, and times it surged when conditions were just right. But it never completely went out. The first European settlers to see it in 1828 mistook the constant plume of smoke for a volcano, not realizing they had encountered a far stranger phenomenon – the oldest known underground coal fire on the planet. By 1829, geologists understood it was the coal itself burning, part of a 235-million-year-old Permian coal layer fueling a fire that had already been active for at least five or six millennia. The eternal flame had been lit, and it has been quietly burning ever since.

The Subterranean Inferno Beneath the Mountain

Descending beneath the surface in our imagination, we enter the realm of the Burning Mountain fire. Thirty meters below ground, where sunlight never reaches, a volume of coal is glowing red-hot, like the heart of a vast furnace. The combustion here is smoldering, not flaming – a slow, low-oxygen burn. It is as if a giant bed of charcoal embers were buried under the rocks, radiating heat. Within the burning seam, temperatures reach astonishing levels – on the order of 1,000°C in the hottest spots. In some pockets, it may climb higher still, creating a blast-furnace effect that can exceed 1200°C and even approach 1700°C in temperature. At such heat, the very rocks are transformed. The overlying sandstones and claystones are being baked like pottery in a kiln. Clays harden into a porcelain-like mineral called mullite, and some rocks fuse into brick-like red clinkers along the fire’s path. The underground fire is literally remaking the mountain from the inside, leaving behind a trail of thermally altered rock and ash.

Above ground, the evidence of this hidden inferno is subtle but unmistakable. You might notice the earth become warm beneath your feet and see thin tendrils of smoke seeping from long cracks in the soil. Yellow-white crystalline deposits crust the ground – not ash from flames, but minerals like sulfur, gypsum, and alum that have steamed out of the burning coal and condensed at the surface. The air carries a faint smell of sulfur, reminiscent of burnt matches, signaling the presence of subterranean fire. The landscape itself bears scars: trees and grasses vanish in the immediate vicinity of the fire’s current location, the soil bleached and reddened by heat. The ground has a buckled, uneven look, where it has sagged into voids left by burnt-out coal or been heaved by the expansion of baked rocks. In one spot, a gully marks where the land collapsed after the seam beneath was consumed, and nearby claystone boulders have been cooked into fragile ceramic lumps – a place aptly nicknamed “the Brick Pits”. It is a scene at once ordinary in appearance and utterly unique: an ecosystem overturned by a fire that moves unseen below, a slow rearrangement of earth driven by heat from within.

Despite its destructive force, the Burning Mountain fire advances with glacial patience. As the coal is consumed, the fire front inches forward, feeding on fresh fuel. It creeps southward at about one meter per year on average – so slow that an observer standing by would perceive no movement at all. Yet over the years, those meters add up. The mountain is effectively alive with fire, its combustion constantly chewing through new coal, causing the ground to crack open ahead of it. Each crack that forms acts like a chimney, funneling oxygen down to the glowing coal and allowing the fire to sustain itself and move onward. In this way the blaze creates its own ventilation system, forever carving a path forward. Nothing on the surface can quell it; rain only turns to steam against the hot rock, and soil only insulates it. The fire has dug in for the long haul, locked in a balance with the mountain that shelters it.

The Slow March of Fire Through Deep Time

Measured on a human timescale, the Burning Mountain fire is almost unfathomably slow – and yet relentless. A single year’s progress is barely a few steps’ length, but after centuries the fire has traveled on the order of kilometers. Geological surveys and local observations have traced a charred, ash-laden path about 6.5 kilometers long through the mountainside, marking the route the fire has taken since its ignition. From this, scientists estimate that the coal seam has been burning for at least 5,500 to 6,000 years. To put that in perspective, if the fire began six millennia ago, it was already alight while humans were building the first cities of Mesopotamia and ancient Egyptians were raising the pyramids. All of recorded human history has unfolded in the time it took this hidden fire to slowly tunnel its way through the coal under Wingen. It is a drama of deep time: an ongoing saga that vastly predates the modern world, yet continues into our present day.

Amazingly, Burning Mountain’s story may be only just beginning. The coal seam that fuels it is part of a substantial Permian deposit stretching through the Hunter Valley, and no one knows exactly how far the fire can travel or how much fuel remains. There is every reason to believe this underground blaze could continue for many thousands of years more. As long as coal and oxygen persist, the flame will keep advancing, meter by meter, indifferent to the passage of time above. Some speculate that the fire could persist for tens of thousands of years into the future – essentially, for as long as it takes to exhaust the coal or until some major geological change snuffs it out. In essence, Burning Mountain is a self-sustaining eternal flame on a geological timescale. It has no natural ending in sight, outliving empires and likely to still be burning long after modern civilization has turned to dust.

A Geological Wonder in Earth’s Story

Standing at the smoky summit of Burning Mountain, one can feel the profound passage of time and the power of Earth’s hidden forces. Here is a fire kindled in our planet’s ancient past that still lives today – a flame that links us to deep time, bridging a gulf of ages. In the grand story of Earth, Burning Mountain is a unique and awe-inspiring chapter: part furnace, part volcano, part time capsule. It is a testament to how dynamic our planet can be, even in what we think of as “solid” ground. The mountain’s ever-burning coal seam reminds us that the Earth is not a static stage but a living, changing system, with chemical reactions and tectonic movements that can play out over millennia.

The sight of smoke rising from the soil and the feel of warmth from ancient coals underfoot underscore the concept that geological change is often slow, yet inexorable. Burning Mountain humbles us with its longevity and steadfastness. Long after we are gone, the fire beneath this hill may still be inching its way forward, quietly reshaping the rocks and writing a chapter of Earth’s history that only future eons will see completed. In the end, Burning Mountain stands as an ever-burning geological wonder – a natural beacon of deep time – reminding all who visit that some of Earth’s most astonishing dramas happen not in sudden catastrophes, but in the slow, persistent workings of nature over ages beyond human comprehension. The mountain of fire will continue its majestic, smoldering saga, as it has since time immemorial, a glowing ember of our planet’s immense and ongoing story.

Here's the video we made on Burning Mountain in New South Wales: