The Donkey Sanctuary just outside Sidmouth. We absolutely love it (and free entry too!).
Afternoon tea at Otterton Mill (which you will pass on your way through to Ladram Bay).
I would strongly recommend the coastal path walk from Ladram Bay to Sidmouth - although it is a steep climb at times the views are absolutely beautiful and you can always reward yourselves with an ice-cream from the 'shop of many flavours' near Sidmouth seafront (Ice-Cream Paradise I think it's called?)
I second World Of Country Life at Sandy Bay, Exmouth. 6 is a good age to get the most out of it (play areas, deer train, goat walking, ferret racing etc.) My boys are older now but both loved a day out there when they were younger.
Pecorama (Beer/Seaton way) - excellent if your DS likes trains. Just remember to check opening times before you go, because it didn't used to be open everyday when DSs were younger (although that could have changed now of course).
Crealy near Exeter (just off M5 J30) is also good fun & the rides are pretty much all suitable for a 6 year old (but probably not the Go Karts). We haven't been yet this year, but last year they did "free returns" too. So if you paid for one day's entry you could return for free whenever you wanted for the next 6 days.
Going a bit farther afield, The Model Village at Babbacombe (Torquay) is always worth a visit as is Bygones just around the corner from The Model Village on the main street. Bygones is a Victorian museum in a shop really. It has a recreation WW1 trench, a Victorian village street with little shops (not working shops) etc. etc. An excellent rainy day visit. We also love the cliff railway down to Oddicombe Beach which is just there in Babbacombe too.
Paignton Zoo is amazing - the best zoo I have ever been to. It is huge & definitely takes a whole day out but is well worth a visit. It is quite expensive though, buying tickets in advance online is slightly cheaper if you have wifi access.
Brixham is a lovely little town (and where I plan to move to when the DCs finish school). Again, well worth a visit.
Sorry for the essay
. If there is anywhere in particular you are thinking of let me know - chances are we could give you a review
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