Krem Umladaw: Journey to the Centre of the Earth

We stood at the edge of the precipice and stared into Krem Umladaw’s endless darkness. A wispy shroud of mist spiralled up from the shaft. Gingerly, I dropped a pebble into the void. It clattered a few times and then disappeared into the silence of the shaft. I gulped. My pebble would have only reached the first pitch, which is what cavers call steep descents and ascents, of this three hundred-and fifty-foot-long shaft that tunnelled into the earth.

“This is it,” wildlife photographer Dhritiman Mukherjee grinned wickedly. It was an audacious dream that was coming to fruition. Our team would be one of only three teams in the world to have explored Krem Umladaw, India’s deepest shaft cave.

Home to some of India’s longest and deepest caves, Meghalaya ranks among the top 10 caving destinations in the world. Caving, or spelunking, is a niche activity — to explore subterranean spaces in the dark, not quite knowing the size of the cave or the challenges the terrain might throw at you. The feat requires a mix of skills, hiking long distances, crawling in mud and over slippery rock surfaces, navigating tight rock niches, and even diving in underwater pools or rivers.

It was Krem Umladaw that had triggered Mukherjee’s interest, culminating in our two week-long caving expedition in Meghalaya. After a week of exploring other caves, our team had now whittled down to three— Mukherjee, caving enthusiast Advaith Keole and myself — who had volunteered to brave Umladaw, the most arduous cave of the expedition. Here, in the pools at the bottom of the cave, over 300 feet below the surface of the earth, lived the object of our quest. An extraordinary cave superstar, the world’s largest known cave-adapted, or troglobitic, blind fish.

The evening light edged past bamboo fronds and trees draped with lianas, barely illuminating the narrow entrance before it was consumed by the black within. Inside, in preparation for our descent, our associates from the Meghalaya Adventurers’ Association (MAA) would be rigging the anchors till late into the night.

To reach Krem Umladaw, we had travelled for two days into the interior of East Jaintia Hills, camping en route in the mountains and then hiking a whole day to reach the valley floor. Here we pitched camp in the rocky riverbed near the entrance of the cave. We were all high on adrenaline and equally filled with trepidation. Would we be able to pull this off? The descent itself was daunting, but the thought uppermost in our minds was about the ascent back to the surface. In anticipation, we had prepared both bodies and minds, losing weight, sharpening climbing techniques, building up courage. A few days earlier, the three of us had also brushed up on our technical climbing skills, particularly the single rope technique, in another cave in East Khasi Hills. We practiced rappelling down long vents and jumarring up vertical sections using a rope ascender, or jumar. The single rope technique, which is what we would be using, is used to climb rocks or trees that are at a sheer 90-degree angle to the surface. Krem Umladaw was a daunting challenge, but we were primed and ready to tackle the prize cave of our expedition.

Early the next morning, we kitted up — protective full body caving suits, helmets, LED headlamps, spare headlights, gloves, and gumboots. Then, we wore our harnesses, descenders, ascenders, chest crawls, and other climbing equipment.

We were finally ready for the descent into Krem Umladaw. We would be descending the narrow vertical shaft one by one as there could be only one person on the rope at any given time. Mukherjee went in first. I was next. As I rappelled down into the darkness, I realised that the plumes of mist I had seen the previous evening were caused by the high levels of humidity down below. The shaft was narrow and slippery, and we had to manoeuvre past incredibly tiny sharp, angled limestone ledges. This led to a startling game of hide-and-seek with the single sliver of sunlight from the entrance, which often disappeared without warning as we descended, only to surprise us with a dramatic shaft of light at the next pitch.

One by one, we slowly descended deeper. Between pitches, I waited on a ledge for my turn on the rope, balancing precariously with my carabiner secured to the safety anchor. Switching off my light to conserve battery, I took in my surroundings. At this depth, the concept of time seemed unreal, day or night, the depths are always cloaked in black. But sounds of life surrounded us. As I waited, I heard the chirrupps of cave crickets echo softly around me. As I marvelled at how life can sustain at these depths, it was my turn to negotiate the belay change from one anchor to the next.

Belay changes require nerves of steel, and this one was particularly tricky. Ahead of me, a team member had needed assistance as he suddenly found himself suspended in mid-air and unable to move, as he had inadvertently locked his chest harness to the anchor. Help came in the form of instructions yelled from above while he extricated himself. I realised that on the rope, each of us was on our own. While Mukherjee and others in the team waited on ledges far above and below in the dark shaft, I willed myself to suspend thought, focussing only on transferring my equipment from one rope to the next. 

Suspended in mid-air, legs dangling, with nothing but the sheer drop below, I wondered what waited for us at the bottom. The high walls on either side were studded with fossilised limestone, some of the most stunning marine fossils that we had seen. As I carefully descended the perfectly sculpted circular shafts of rock, I felt like I was truly on a journey to the centre of the Earth.

We finally completed the last pitch. At last, after what had seemed like ages, my feet touched the floor of the cave, startling a frog that quickly leaped out of sight. The enormous cave now stretched out in front of me, with a large horizontal passage that ran almost three kilometres. We were eager to explore further, and navigated past narrow passages and pools of water. I was surprised to see in the light of my headlamp, seeds that had germinated at the bottom of the cave, brave and tiny fragile leaves that would never see the light of day.

I followed slowly, looking for more signs of life. Ahead, I spotted the glow of a head torch, a sign that Mukherjee had already found the pools we were looking for. I quickened my pace, and there they were, dozens of very large blind fish, snow white in the limpid blue pools three hundred and fifty feet below the earth lit up by our torches. It was for this that we had undertaken this journey.

Cave-adapted or troglobitic fish are typically small, owing to the low availability of nutrients in their environment. The world’s 250 species of blind cave fish are all between 2 to 13 cm, but astonishingly these fish in Umladaw measure almost 40 cm. Discovered in 2019, the Umladaw fish is also different from other cave fish discovered in Meghalaya, like the Schistura larketensis, a kind of loach discovered in Larket village in East Jaintia hills.

Professor Khlur Mukhim, who specialises in studying cave life tells me that he has sent genetic samples of Umladaw’s fish for sequencing. This might shed some light on this mysterious creature. Based on the characteristics of the fish, like scales, fin rays and anatomy, he thinks that it is possibly related to the surface-dwelling chocolate mahseer, (Neolissochilus hexagonolepis), a near threatened freshwater species.

Krem Umladaw is an underground sink in the bed of a seasonal, above-ground river. The cave floods during the monsoon when the river flows in full spate, and is accessible only during the dry season. There are no bats, and therefore no bat guano, or any other known source of food available. What then do the fish feed on? What makes them so large? It is possible that they are feeding primarily on vegetation washed underground by rain. It is yet only a postulate; it is difficult to say for certain. 

It is an indescribable feeling to see in person this population that has been losing the faculty of sight and pigmentation over generations, evolving to life in the dark and possibly becoming a distinct species. What other changes would be in the making? Beyond the pools, the faint sound of running water drew us to explore the horizontal passage further. Turning a -corner, I spotted a burst of green against the rock. It was a snake, a Pope’s pit viper (Trimeresurus popeiorum), 350 feet below the surface — an inexplicable bonus sighting. Following the gurgling, we navigated through pools to reach the underground river. Here I saw another spectacular sight — dozens of the largest blind fish jumping up out of the water, swimming against the current, flashes of white against the inky darkness.

Soon it was time to begin the gruelling ascent. Later we would realise that this took us four hours — almost half of the ten hours we spent inside Krem Umladaw. It was an excruciating exercise one haul at a time, a vertical frog crawl, my face inches from the limestone wall. Even as I jumared up, I paused to observe cave flora in the limestone walls, powdery white drops in a crack, possibly some kind of fungi. It hit me that there was so much more to this cave than we knew.

Krem Umladaw was first surveyed in 2019 by MAA, under an initiative to document Meghalaya’s caves called ‘Abode of the Clouds Expedition’, an international collaboration with cavers from across the world. Brian Kharpran Daly, general secretary of the MAA, points out how limestone caves like this are under threat from cement production, coal mining, and water pollution. “These activities could cause the collapse of caves and the extinction of cave species even before they are documented and protected,” he says.

It was dark when we finally reached the top. We were exhausted but above all triumphant. Later, as I learn that, based on information gleaned from a stalactite in a Meghalayan cave, the geological time scale we currently live in has been officially named the ‘Meghalayan Age’.

I think of the rich fossil-studded limestone that surrounded me in the shaft. As I marvel at this otherworldly habitat, I am left feeling, more than ever, that this world of rocks and water stretches back to a time that is beyond imagination. A world in which homo sapiens have just arrived.