Buchan Caves is part closed to the border of NSW and Victoria. It is a sandstone still developing stage. It was a tight squeeze and you basically need good fitness to move around. I have experienced in other caves and this particular cave tour was less relaxing.
The last cave I was in was in at Wellington Cave in Central NSW. It was more spectacular and less stressful as there was a small tour group. The tour guide was less pressure to push people through the cave. You have to excused the Buchan Caves staff as it was peak season, but if you have a chance then go on off peak season. Maybe you might enjoy it more than I did.