Ground cover ... the Big Hole in Deua National Park.Credit: Ben Stubbs
Sometimes curiosity is an unavoidable beast, gnawing away at the unfortunate soul until it is sated. In 1862 a foolhardy young man named Boxall was set upon by this curiosity. In the deep bushland of south-eastern NSW, he rested four lengthy saplings across the edge of a hole, the bottom of which was beyond his view.
To the bemusement of onlookers, he then fastened a rope between the saplings and his waist and leapt without hesitation into the chasm. After being lowered down further into the darkness, he reached the floor and lit a candle for those waiting in anticipation above.
Walking among the two-metre ferns and the rubble that carpeted the bottom, Boxall had finally satisfied his compulsion. He was 96 metres below the surface of what is now known as the Big Hole.
The coastal mountain ranges of southern NSW are often overlooked by travellers heading straight to the surf or the snow. On a spare weekend we decide to explore a little of this uncluttered area and venture from the Snowy Mountains Highway across the corrugated dirt roads into the Deua National Park.
We drive past the great sweeps of Monaro farmland and treeless rises and head into the untracked wilderness that fills much of the gap between the mountains and the sea.
The 122,000-hectare Deua National Park is a wild and windswept claw that pushes down towards the coastal town of Moruya. Along dirt tracks and farms of sheep and llamas, the Berlang camping ground opens out towards the copper-coloured rapids of the Shoalhaven River.
We have many caving and hiking options and we decide on the 13-kilometre Marble Arch walking circuit. Hopping across the stones that ford the river, we hear a tidal roar through the trees ahead. It sounds strangely similar to the big swells smashing against the headlands of the South Coast.
Hoping we haven't missed the turn and ventured far off-course, we track up through the prostrate heath brush on Bald Hill to get our bearings. As we hit the top of the rise, the source of the noise is revealed. A near gale-force wind is battering its way through the eucalypts on a ridge that twists through the north-west corner of the national park. Continuing along through the gums and acacia forest that struggle up from the ochre earth, we come across a sign warning us to watch out for a big hole ahead.
Little do we realise that it is the Big Hole.
It was discovered by settlers in 1832, when surveyors mapping the area stumbled across the gigantic puncture in the ground. This deep hole looks as if a cork has neatly and abruptly popped out, with the trees still peering over the edge, as if surprised by the oddity below them. It is believed to be the 350 million-year-old remnants of a vast limestone cavern that collapsed, leaving soft tree ferns and a solitary lyre bird nesting in the darkness of the bottom.
Gazing over the lip from behind a tree dangling into the centre, I fight the knots in my stomach and edge a little closer. It looks as if a concealed path or a cave snakes across from the ferns at the bottom but it is impossible to tell from above. Modern-day adventurers can lower themselves into the Big Hole throughout the year with various abseiling groups.
Back up on top, a sturdy viewing platform nudges out over the hole, with safety bars ringing the area and signs alerting people to the danger. Reading the plaque, it seems the discovery of the Big Hole must have been quite abrupt for one man, who inadvertently stumbled across it in 1884 and fell in.
As we continue further, the dusty track winds past the occasional echidna and wombat hole and the mustard-coloured termite mounds that prop against the trees like dirt sarcophagi.
After cresting a rise that looks out to the unbroken valleys moulding the Deua River, the track drops steeply towards the Marble Arch. The limestone cave system is a sanctuary for the brightly coloured tree ferns and creepers that plaster the walls descending into its heart.
As we climb over the lichen-encrusted boulders into the cave, we are guided by nothing but the echoing drip, drip, drip of creek run-off resounding throughout the chasm. We see stalactites and thick veins of marble on the roof. At the entrance, a fallen boulder the size of a four-wheel-drive is lodged in the mouth of the cave. The Marble Arch is of important scientific and archaeological value because of its resident owl population. Of the 106 bird species in the park, the powerful owl (the name of the species, not a description) has left pellet deposits through the subterranean corridor. These deposits are the regurgitated bones and fur of its prey. In some parts of the Marble Arch, the remains of the small mammals and birds are thought to be thousands of years old.
As we peek into the opening, the rolling clouds above are shifting from puffy white to dense grey. We clamber up the sides of the arch, picking leeches off our boots, and scramble to the top.
It looks as though flash floods would fill the funnel of the Marble Arch in a matter of minutes, so we don't linger.
As we head back up the incline it is possible to see across the tops of the peaks towards the Wadbilliga National Park. Less than an hour's drive from the Deua National Park are the beautiful rainforests of the Wadbilliga, which shelters the Tuross, Wadbilliga and Brogo rivers and the impressive Tuross Falls that spout from the Cascades.
The pockets of woodland are also home to the endangered spotted-tail quoll and many accessible walking tracks follow on from the trails in the Deua.
As we loop back from the Marble Arch, I have a tingling itch while hiking up the hill. The itch grows as we clamber up past the stringybarks. Approaching the Big Hole again, I can't ignore it any longer and I venture away from the safety of the viewing platform and look down into its depths, undisturbed by the weather above.
With the wind blowing across the sides of the hole threatening to tip me in, I understand for a moment the compulsion Boxall must have felt on this same ledge, wanting to know what was at the bottom. I peer into the mysterious fissure for the last time. Backing away as the rain begins to fall, I leave the Big Hole unconquered.
When I wander back to the track on the edge of the Deua National Park, the trees sway and moan in the tempest and my curiosity is left unquenched. For now.
FAST FACTS
The Deua National Park is 320 kilometres south of Sydney and 100 kilometres south-east of Canberra. There is no public transport to the park.
Camping costs $5 a person at the Berlang camping ground, on a bank of the Shoalhaven River. See nationalparks.nsw.gov.au.
Sign up for the Traveller Deals newsletter
Get exclusive travel deals delivered straight to your inbox. Sign up now.