I’m not sure who first “discovered” what’s been called the Mega Cave on the Central Coast, but a rough bushwalking pad makes this enormous shelter relatively accessible. It does require some navigation skills and bushwalking experience, as it’s easy to lose the informal track which connects two firetrails.
There are a few different ways you can approach the cave; we started from Myoora Road off the old Pacific Highway. Just before Myoora Road enters a private property, a locked gate marks the start of the Powerline Firetrail.
About 300m along the Powerline Firetrail from the gate there’s a junction with another firetrail. Turn left for optional detour to the Mooney Mooney Aboriginal Site. Described as “one of the most extensive art galleries in the Sydney-Hawkesbury district”, the site includes two rainbow serpents and an intriguing bulbous-headed anthropomorphic figure (one of only four recorded in the Sydney area).
After returning the same way to the Powerline Trail, turn left (south) after about 200m onto an unnamed firetrail – this is the start the Mega Cave loop, which you can do in either direction. The firetrail is a little overgrown in places but easy to follow.
There’s one very short section where a bit of bush-bashing is required – you can see the firetrail continuing on the other side of the scrub, but there’s no obvious track. Or perhaps we missed a sharp bend in the firetrail. Next to the firetrail on the other side of this scrub is a large cage protecting part of the Jemena Gas Networks trunk pipeline which distributes gas between Sydney and Newcastle. It’s a slightly odd sight in the middle of the bush.
The firetrail now descends quite steeply toward the valley, with the M1 Pacific Motorway (F3 Freeway) and Mooney Mooney Bridge visible in the distance. Just before the firetrail abruptly stops is the start of the bushwalking track to the Mega Cave (-33.42964, 151.25943).
The faint bushwalking trail is becoming more obvious as the Mega Cave gets more popular, and ribbons and the occasional rock cairn also mark the route.
The trail generally follows the contour of the steep fairly steep valley, crossing a small creek before reaching the base of an enormous cliff.
A bit further along this cliff is the Mega Cave, an enormous shelter that is both tall, long and deep.
It’s hard to capture the size of the cave, but the two tiny people at the bottom right of the photo give you a sense of scale.
The trail then continues past the Mega Cave, with a few more overhangs along the base of the cliff-line – but none as large or deep as the Mega Cave.
If it’s been raining (we visited a few days after a wet week) you’ll pass a small but picturesque waterfall whihc tumbles over the fern-covered cliff.
A bit further on, a gap in the bush provides another view over the M1 and Mooney Mooney Bridge, and the Mooney Mooney Creek.
The trail ascends a little, with the vegetation changing from semi-rainforest to dry sclerophyll, before it meets the Powerline Firetrail.
The rest of the Mega Cave Loop is easy walking, as it follows the Powerline Firetrail all the way back to Myoora Road.
Although it’s a fairly short loop, allow a couple of hours as the bushwalking track is a bit slow-going.
Getting to the Brisbane Water Mega Cave
For the shortest route to the Mega Cave, you can start on the Old Pacific Highway at -33.429895, 151.264284 – this makes the loop about 2.7km in length. You can park along the shoulder of the road, although it is quite narrow.
The recommended starting point as described above starts about 650m further north at the start of the unsealed Myoora Road. There is parking along the start of the road for a few cars. This is about 11km (10min drive) from Gosford or 46km (35min) north of Hornsby.