Low walking day out from Bath?

[Solasum]

Any local knowledge of somewhere we can go today within an hour’s drive of Bath that both slightly immobile grandparents and a 5 yo can enjoy?

I was thinking Cheddar Gorge, but then realised my dad would probably not be able to do anything at all as he can’t walk far.

We did Wookey hole not long ago.

How about Longleat safari park?

Stonehenge ?

The harbour side area of Bristol. It's all level and there's plenty of bars and cafes to stop off at for a drink or bite to eat.
Catch the train to Temple Meads and take the ferry that runs from the back of the station . If you get a hop on hop off ticket you can get off at the SS Great Britain and the near the Underfall Yard and visit them.

Wells cathedral? Has a nice tea shop too.

Dyrham Park?

@MrsMoastyToasty. Day successfully spent at the Harbour, thank you.

Thanks for all the other suggestions!

No problem, sola. I aim to please. It's one of my favourite jaunts.