Cave Flat is after the Yass turnoff on the fwy now known as Burrinjuck Dam. This is not far from Canberra Australia’s Capital City .
These were dry caves until the Dam was built and the valley was flooded.The water depth in these caves changes due to the Dam levels raising and falling. There is a good camping area on site or big cabins to hire. This lake is a very popular fishing area.
The formations in these black limestone caves are WHITE so they stand out. The main caves are in an Island in the middle of the Lake so you need a boat to get to them.In a drought you can drive a 4×4 out to the island. You can hire a boat from the camping ground office but you need to book one. You need to find out the water level and vis before you plan your trip.
As you can see in photos below. top pic is at 70% and bottom one at 7%.Here is a good link to find out Dam levels. There is approx 25 caves in this region only 3 are worth diving. Water Storage chart