Bungonia B4-5 Caves


I’m sitting alone, resting against a rock. The roof is probably 10cm away, I’m not sure – I’ve turned my headtorch off to save battery and it's pitch black. Slightly peckish I reach for my bag, but before I can, comes the jarring thwack of my helmet hitting the roof. Turns out it was only 2cm away…

Faithful recreation of what you could see with lights off

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Welcome to caving, an adventure sport where people squeeze and crawl their way through tiny (and sometimes unimaginably huge) holes in the ground that they call “caves”, containing some of the most beautiful formations you’ve never seen.

We’re at Bungonia National Park today (as part of the Bungonia Palooza), 2 hours south of Sydney, near Goulburn. Bungonia’s caves are some of the deepest on the Australian Mainland, lying within the Bungonia Limestone Belt, bounded to the north, east, and south by steep gullies and gorges off the Shoalhaven River. The park lies across the traditional lands of the Njunawal tribal group, the northwest corner of the Wandandian tribal territory and the southern boundary of the Gandangara tribal group.

Before our journey into the underground can start, I go with my overlords to watch them help set up ropes for the exit. Today’s cave doesn’t require any abseiling or rope skills per se, but the exit involves negotiating two chimney-like slots, made significantly easier with a handline or rope ladder. Once set up, we head back to the carpark to join everyone else and get going.

The entrance to the B5 cave throws you right in the deep end, quite literally. You descend down a little rocky chute, and two steps in front of you lies a 4 metre drop leading to a further stepped 11 metre drop. Safely circumventing that with the help of a handline, we climb up through a hole and into a long stretch of tunnel, leading to the Upper Aven.

The entrance to the B5 Cave

The Upper Aven is quite an anomaly in the B4-5 caves – most of the cave system is quite dry and dusty, but here you see lots of wet flowstone, forming shawls, stalactites, all the good stuff. I would attach a photo but the only photo I have makes it look like some devilish formation in low light; it would be a disgrace to upload that. Just imagine cool shiny smooth rock.

Sian in the Cement Bag

After lots of time spent ooh’ing and aah’ing at the structures, paired with a mini geology lesson from Zee and a chorus of joyful exclamations from Sam (a mere fraction of what was to come), we continued back on our way out of the Upper Aven and onto the Cement Bag. Another dusty crawl - who could have guessed from the name! This time, the crawl ended at the Hairy Traverse.

One thing you’ll find about most of these names is that they capture the essence of these cave features quite perfectly. The Hairy Traverse has you inch your way down a narrow rock shelf, gripping a chain for support, as a massive drop looms just millimetres away on your left. Words cannot do this justice and I invite you to view this picture on David Noble’s photoblog to really raise those hairs instead.

The vanilla method to descend the chain would be feet first, face the wall, hug the chain, and manoeuvre downwards. Some of us decided to take a spicier method, descending headfirst: hands in front of you gripping the chain while sliding down. Almost like that one kid in the playground who would take the slide headfirst and then faceplant the sandy floor (except we’re pros, we would never faceplant the floor). A little scary, but 10/10 would recommend.

While the rest of the group descended the hairy traverse, the early descenders got a chance to have a little explore of the little chasm we descended into, putting their squeeze skills to the test. We continue on to the little portal connecting the B4 and B5 caves. Doing well for time and with lots of hype within the group, we stash our bags at the Connection Aven and decide to visit the Devil’s Kitchen.

The Devil’s Kitchen is a large chamber that is at the bottom of the large drop we skirted past in the beginning. The standard way of reaching the devil’s kitchen is to abseil down that drop, however with favourable weather conditions and a bit of elbow grease on a shovel, you can crawl through the long way, through some tight squeezes.

This was my second time in the B4-5 cave. On my first trip, which was also my first ever time caving, we had attempted to visit the Devil’s Kitchen. However, I bailed out halfway down this long squeezy section, it was a bit too tight for my liking. I also didn’t miss much, as it turns out the passage to the Devil’s Kitchen was too silted up to squeeze through. (With rain and other natural processes, dirt and sediment gets washed down the cave. This passage is one of the lowest points of this cave, and hence often gets blocked up).

I will gladly let you know that this time I successfully made it down this big squeezy section! {insert soppy self-growth quote here} And to our relief, there was even a manageable amount of sediment at the bottom.

Zee digging at the hole

After a bit of hand digging help, our resident cave rat was able to duck under and make his way through the micro-hole and into the Devil’s Kitchen, where a large shovel(!!) was found and passed back to our side. A lot more elbow grease from Zee later (absolute legend), we were all able to make our way through the now less-micro hole.

As if the squeezing wasn’t enough already, after our little visit to the Devil’s Kitchen the group decided to attempt the B4-5 Extension. This is an even narrower squeeze-crawl through a long long passage, leading to the “Coffin Chamber” and beyond. The name alone was enough to put me off, but taking one look at the crawl they were about to attempt sealed the un-deal for me. I waited in the Junction Chamber while the rest of the group attempted the extension crawl to the Coffin Chamber, with only an abnormally large spider keeping me company in the dark (How did it even get down there? What does it eat? Does it have family?). I was soon after joined by another member who’d decided the crawl was a bit too much (glad to know I’m not the only one), and after a while, the group came back.

Hearing their stories made me even more glad I didn’t join them – apparently the cave got so tight that at one point they had to remove their helmets.

We returned to the Connection Aven, fuelled only by the prospect of chocolate sitting in our stashed bags. On reaching the bag stash it turned out the bags had been moved to Kings Cross, a bit further away… Like zombies driven by their insatiable hunger, we slogged on to Kings Cross, finally reunited with our saviour. We wolfed down our snacks that we’d brought, and discovered that some people had some very interesting dietary choices.

Sam eating a block of parmesan, chocolate, and an apple simultaneously.

Much like the Kings Cross station, B4’s Kings Cross is the centre of a labyrinth of tunnels, some of which contain little fossils that give the B4 Fossil Cave its name. Also peculiar about this Kings Cross is the installation of a massive metal ladder and little bridge connecting a little drop. It is really a mystery how they got this structure down here.

Metal ladder and bridge at Kings Cross

At this point we are fairly close to the finish line and decide to minimise faff, and make our way to the exit. Hah, not without another weirdly tight squeeze! You got excited there, didn’t you?

Through that tight squeeze we arrived at the Signature Chamber, containing a large number of graffiti signatures on the walls, the originals of which date back at least 40 years as found on our similarly old map.

Following that unfortunate encounter (please leave caves as you found them) it is up another little chute, through a large canyon-like constricted section, and up the wire rope ladder we’d set up earlier. A thing to note about caving ladders is that they are anchored at the top, and have wire for bones, meaning they have no rigid structure. You need to climb up in a very specific way to avoid flopping around like that inflatable tube at the car dealership.

At the top of this ladder we see our first glimpse of natural light in 5 hours. I take possibly the deepest breath I have breathed, and savour the cool crisp winter breeze. Believe me when I say that the air has never been tastier. It’s funny - while inside the cave you don’t realise that you’ve been starved of this delicious air for so long.

Salvation
Eight people holding muddy overalls
The crew, part 2: post cave.

We make our way back to the car, and as the sun starts to hide – it’s 4:45pm – we dash to Adam’s Lookout. What better way to end the day than to watch the sunset (oh, and hot showers)!

A special thanks to our amazing trip leaders Zee and Harry, and Cindy for organising the 2024 Bungonia Palooza!