AIBU asking for suggested meet up activities for Grandparents & Teens

[ChristmasTreeRipoff]

Using the summer hols to meet up with the inlaws but stumped for a something that wouldn't tire out the 70 year olds but would also not induce boredom in the teens.
To be fair the teens are good but they see my ex-H's parents so infrequently we need to have an activity so it doesn't just become a 20 questions on what's going on in each others lives whilst eating a meal.

Any suggestions ?

Sussex/Surrey region but non region specific suggestions helpful too.

Thanks

Do any of them have hobbies they could share?
My dad and teen son go fishing together, occasionally my husband goes too. It's a hobby and skill of my dad's he's passing along but my son is interested to learn. My dad also plays bowls - not great for teens - but this transfers to bowling. My son also enjoys golf, so both of them will happily have a game of mini golf.
My daughter and my mum have a shared hobby in sewing. Again a skill my mum has which she is passing down and my daughter loves it. She has her own sewing machine and does lots between my parents visits (and quite fancies a career in costume creation). They can spend hours looking at sewing magazines and patterns and shopping for material and did a project together. They are also partial to a general shopping day.
Tbh my parents are also happy to watch the kids do their things. They will come and watch DD roller skating or ice skating, and they'd think nothing of walking round a theme park and 'looking after the bags'.
We've also had some great days out in London. My mum shares a love of history with DS so we can go to pretty much any museum, and DD was into astrology one year so we went on the river boat from Waterloo to Greenwich and went to the observatory.

Do you mean days out? As long as there’s a tea room/ice cream hut involved, I find 70s and teens can both be happy at any place like wildlife park/museum/NT property etc.

Any specific interests of either teens or 70s? For example my dad loves a few hours rock-pooling, so a beach trip is a winner - fish & chips, I’ve cream, maybe short game of cricket etc then camping chairs for grown ups and teens bugger off a bit!

We are fairly local to you - how about a little walk along the beach at Lancing then brunch/lunch at Perch on Lancing Beach? Or any other nice spot with a decent cafe? Denbies in Dorking? Redhill Aerodrome? Pick your own farm shop and lunch after?

I'd go for a beach with a pub or cafe next to it, walk along, teens can skim stones, swim, SUP etc, grandparents can amble along then enjoy a meal drinks etc

Thanks folks

Will start looking into stuff.

Crazy golf? Not too tiring but fun

RHS Wisley? Perhaps not riveting for the teens but a lovely place and you can buy annual passes which are good value (you can also use Tesco clubcard points to go there). Nice walk for the older people, stop for tea and cake etc.