Two under the one log near the small dam (which had a little water in it). There was a third frog under another log about 15 m away. Sorry, I didn't realise until I looked at the photos on my laptop how muddy they were.
Ta. I remembered from last time I found a frog and was as gentle as possible turning it over with a small stick. Hopefully it is not too traumatised and will go on to produce many froglets for me to pester in the future.