Hidden tunnel near Jervis Bay will lead you here: map, video
With a boyish grin wider than the Sydney Harbour Bridge, I drop to all fours and creep expectantly into the abyss. Gosangs Tunnel has been on my bucket list for years, and today I'm finally crawling into the 30-metre-long chasm, an elevated sea cave that's been shaped by a millennia of storms smashing into Point Perpendicular near Jervis Bay.
However, I've barely managed to haul my ample posterior into the concealed cavern when a gush of wind suddenly hits me straight in the face. It sounds (and feels!) like a freight train and before I have a chance to grab my hat, the force of the wind blows my Akubra clean off my noggin.
After bouncing off the rocky roof of the tunnel, my trusty headpiece lands eventually ahead of me, just out of reach. It balances precariously on the edge a 30 centimetre-wide fault line which runs through the entire length of the tunnel. Stretching ever muscle in my arms I extend out my fingertips and scoop it up just before another gust of wind slams me in the face.
Phew! With my ruffled piece of rabbit fur now safely tucked away into my backpack, I continue hatless, deeper into the tunnel.
Not small enough for claustrophobes to start frothing at the mouth, at about two metres at its widest and less than a metre high, Gosangs tunnel can, however, be a bit of a challenge to negotiate. While the more flexible could duck-waddle through, much to the detriment to a couple of layers of skin on my knees, your brave columnist instead chooses to continue to clamber along on all fours.
But wow, it's so worth it. The tunnel ends abruptly, opening onto a rock platform suspended high above the Tasman Sea. What a view. It would make a great vantage spot to watch whales returning south to Antarctic waters for summer, or just to sit and contemplate the endless blue horizon. I do neither and instead slap Band-Aids all over my badly grazed knees.
Intriguingly, it's not as blustery on the exposed rock ledge as inside the tunnel. It's as almost as if the tunnel curiously creates its own squall. If it does, it's not the only magic around here, for just a short walk back through the tunnel and 500 metres or so southwards is Mermaid Inlet.
Some say this spectacular chasm partially filled with giant slabs of rock was the result of the Ice Age while others argue a 70-metre high tsunamis once smashed into this part of the coastline. I scour the cliff face for any sign of the fabled half-woman, half-fish beauty but suspect the rock fisherman resplendent in stubbies and sinking cans of VB on the lower ledge may have frightened her away.
From Mermaids Inlet you can trace your steps back to the start of the walk (2km away), or the fitter could keep trekking south on the 9 km loop which passes through coastal heath and even more sandstone cliffs punctuated by fabulous views up and down the coast.
There aren't many bushwalks that lead to coastal scapes as dramatic as those on this easy relatively easy stroll. Throw in the knock-out beach and fish 'n' chip shop at the track head and you'd be hard-pressed finding a better day trip to our South Coast.
Just be sure to secure your hat.
Gosangs Tunnel: This sea cave is one of several highlights on the 9km Coomies loop walking track which starts at the north-eastern end of Beecroft Parade, Currarong. Currarong is a 3-hour drive from Canberra.
Kid-friendly? Due to the steep drop-off at the end of the tunnel, I'd recommend against bringing young children here. Even with older kids, be sure to keep a close watch on them.
Did You Know? Non-karst caves in seaside cliffs like Gosangs tunnel are formed by wave action and salt eroding rocks, especially where rock strata contains joints, bedding planes, dykes, faults or other zones of weakness that are more susceptible to erosion. Over 200 sea caves are found along the NSW coastline.
Also try: Box Vale Walking Track
One of the most rewarding half-day walks in the Southern Highlands is the Box Vale Walking Track which follows the route of an abandoned mining railway line through palm-lined cuttings, along embankments now festooned in rainforest, and best of all, into a sandstone tunnel.
Length: Measuring 84-metres long, this tunnel is short enough that you won't need a torch, but sufficiently long that you'll need to be careful not to trip over corrugations where the railway sleepers once lay.
Kid-friendly: Kids (and big kids!) with a moderate level of fitness.
Expect: Picnic tables are located at both the track head and at the lookout beyond the tunnel. There are BBQs and toilets near the car park.
Explore: The start of the Box Vale Walking Track is about 250 metres off the old Hume Highway at Welby. The turn-off for the track head is signposted but is easy to miss — it is 3.7 kilometres west of Mittagong and 0.8 kilometres east of the Wombeyan Caves Road.
Although the surrounding country is steep and rocky, the track itself is relatively flat and the return walk (8.8 kilometres in total) takes about three hours.