Wish I knew what I know now...
We arrived at Port Arthur at 2.30 in the afternoon after a 2 hour dirve. Unfortunately that was too late to see much of the place.
I recommend staying somewhere close by and planning to go to Port Arthur two days in a row - which is included in the entry fee.
We went on the cruise (included in the entry fee) and it was pleasant, and informative.
The small part that we DID see was VERY interesting and the kids enjoyed the old buildings.
We really missed out by getting there late and I am disappointed.