Pebbly Beach, north of Batemans Bay, in the Murramarang National Park.
Beautiful camping, kangaroos on the beach, gemstone pebbles (agates) on the beach 100m to the south, kids love it!

Might be a bit busy after Christmas though.
http://www.environment.nsw.gov.au/na....aspx?id=N0025 follow the links for the details on Pebbly Beach, phone numbers, booking etc.
Cheers

Chris