Colwyn Bay this Saturday and it’s looking wet! Indoor activities?

[Jungfraujoch]

Conwy Castle is one option I know. Anything else please?

Coppermine on Llandudno great Orm, Angel Bay to see the seals, they don't mind the weather.
Whilst Conwy Castle is good I feel a walk around the walls is better value as it's free. couple of very good toy and Kids Tat shops in Conwy, remember to tell the kids its a medieval walled city with great history.
https://www.donthibernate.co.uk/conwy/

Big Indoor swimming pool in Rhyl but its expensive https://sc2rhyl.co.uk/waterpark/
Cinema In Colwyn Bay?
https://theatrcolwyn.co.uk

Rhos On Sea has a few nice cafes
https://marmaladekitchen.co.uk/index.html
A short drive to the Flower pot cafe but its great, possibly the best around, just 5 mins off the A55 at St Asaph (The second Smallest City in the UK)
https://www.tripadvisor.co.uk/Restaurant_Review-g663600-d19859961-Reviews-The_Flowerpot_Cafe-St_Asaph_Denbighshire_North_Wales_Wales.html

Thank you - copper mine sounds interesting. No kids just me and DH!

Tweed Mill in St Asaph, if you fancy a bit of shopping also you can have lunch there