Hi! I’m a Donostiarra (San Sebastián local). It’s not Spanish at all, don’t come expecting Spain!
If you can, book in advance to eat at the culinary university in San Sebastián (Basque Culinary Centre).
If you have some money book a one Michelin star dinner at the Mirador de Ulia - incredible mountain clifftop restaurant
If you have lots of money book a 3 star - Arzak, Akelarre...
If you have a car and you’re going between Bilbao and San Sebastián, stop at San Juan de Gaztelugatxe (it’s the most breathtaking place - it is dragon stone in game of Thrones.
Also on the way is Guernica which has an interesting museum.
In San Sebastián they have just opened a new sculpture park - Chillida Leku- which is nice for peace and quiet. I’d avoid the science museum unless it’s raining. It’s ok but will have all the kids summer camps on.
It’s a bit cold for the beach at the moment.
Igueldo theme park is sweet but your children might be a little old for it. Still worth it for the Views. Pintxos in the old part are lovely but expensive so head over the bridge to gros.
For a day trip with kids your age, this is my absolute favourite, incredible but fairly off the beaten track treat:
Albaola maritime centre as mentioned above is great - take the metro (topo) to pasaia donibane, walk right through it’s one street stopping off at the victor hugo house on the way. Go as far as the path takes you, right around the headland almost out into the sea, then youlll find a great little bar for some tapas. Then take the tiny over the bay to the other side and stop at the maritime museum. See the whale ship being built in real time. Then keep walking to the end of the path and you’ll find some steps where the bay opens onto the sea. Go up them and walk in a straight line right over the mountain, part of the st James way with views that look like something out of Jurassic park. Come down back into San Sebastián on the other side. If you can time it for sunset you won’t regret it!