Stories from the mountain summer

Underground Adventure

Mysterious paradise in the eternal ice

Wondrous ice formations, mysterious cavities and frozen waterfalls – deep in the heart of the Hintertux Glacier, twelve years ago, Zillertal local Roman Erler discovered a system of caves like no other in the world, which is still shrouded in mystery to this very day: the Natur Eis Palast (Nature’s Ice Palace).

He very nearly walked straight past it. But then, the small, perhaps ten-centimetre-long, gap on the side of a wall of ice on the Hintertux Glacier caught his eye. When Roman Erler first risked peeking into the crack, all he could see was a black nothingness unlike anything the experienced mountain pioneer had ever seen before. A mysterious expanse of impenetrable darkness. “I instantly felt that something very special was hidden behind the wall”, the man with the crisp Zillertal accent fondly recalls about this momentous day twelve years ago. He also recalls how he returned to the site and used a heavy ice axe and plenty of primal Tyrolean force to expand the small hole to a shoulder-width passage. How the light from his powerful torch was only thrown back at him by stalactites of glittering ice many metres away. And how his heart pounded with excitement and his breath caught for a moment. He instantly wanted to share his discovery – and naturally asked his wife Marlies Erler to be the first to join him in the belly of the glacier. She immediately had the idea that brings joy to thousands of visitors today: “We have to make this natural phenomenon accessible to the general public!” And no sooner was this said than done.

Shimmering surprises

Even now, Erler still talks about this special day as though it were only yesterday. We are standing at the entrance to the Natur Eis Palast, as his miraculous discovery was baptised several months after it was first explored. The tall man tells of the thousands of hours that it took to explore the cave system and finally make it accessible to visitors. Of the hundreds of metres of cable that had to be laid, the staircases that had to be integrated and the handholds that had to be installed – so that even inquisitive amateur cave explorers can go on a journey of discovery. After all, sparkling surprises await visitors’ awe around every corner. In fact, Roman Erler has now discovered small and large halls of ice on three different levels. Many of these are accessible to the public, some he is currently exploring himself and some are even cordoned off for scientific purposes. After all, while we are captivated by the up-to-eightmetre-high stalactites, the enormous frozen waterfalls and, above all, the unique underground water world including a boat trip and stand-up paddling options, the subject matters get far more complex just few (climbable) walls of ice away.

“Since discovering the Natur Eis Palast, we’ve
been working closely with researchers from all
over the world”

Roman Erler, discoverer of the glacier cave

Erler: “Since making the discovery, we’ve been working closely with researchers from all over the world.” Consequently, the tiniest ice-dwelling organisms, such as extremophile germs and bacteria, which are resistant to antibiotics, are being scientifically studied. Above all, however, the experts are focussed on how this enormous system of underground chambers could have formed in the heart of the Hintertux Glacier. “As the glacier is frozen solid to its base here, the ice cannot glide like it does elsewhere in the valley. When subjected to pressure though, the ice responds with plastic deformation and is displaced in the deeper areas where the pressure is at its greatest. When this happens, tensile forces open up cavities inside the body of ice.” This resulted in a system of cavities, which can exist for much longer than “conventional” glacial crevasses. And above all, a system unlike any other in the world!

Spectacular deep excavation. It is only logical that this discovery sparked an inquisitive spirit in researchers around the world. But it also sparked one in Erler himself. To literally get to the bottom of how the cave was formed, he quickly dug a shaft several metres wide and 52 metres deep into the glacier’s ice – to its bottom. An almost impossible seeming endeavour that was ultimately rewarded with another breathtaking finding: by inserting a plumb bob into the shaft, Erler was able to prove that, unlike in other areas, this section of the Hintertux Glacier does not move a single millimetre. He takes on a serious tone as he explains that glaciers usually “glide” across a thin layer of water, but this is not the case here. Here, the glacier is frozen to its base.

An icy mystery. There is just one matter that is foxing both scientists and the passionate cave researcher: they have so far been unable to verify the age of the glacier and the Natur Eis Palast. This is because the body of ice that contains the Natur Eis Palast is frozen to its base and decoupled from the main ice flow. This means that the ice, especially that which is in contact with the rocky glacier bed, will be very, very old. Erler: “You normally find the oldest glacial ice (dating back 500 – 1,000 years) at the lower end of the tongue. The ice around the Natur Eis Palast has to be far older than that.” However, the age is a question that still remains unanswered. One thing is very much certain though: Roman Erler will keep researching the icy shafts, passageways and catacombs until he finally finds the clue he is looking for – and can answer the unresolved question.

Image: Bernhard Huber and text: Johannes Stühlinger
Zillertal magazine Summer 2020

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