Wombeyan Caves rd is closed due to a landslide. There is no access to the caves via Mittagong. You need to go via Goulburn and Taralga to get there.
Did this run about a month ago and found out when we got to the caves. We started from the North. The detour adds about an hour and a half to the trip. Wombeyan Caves is a ghost town at the moment.