2 days in Santander? Or Barcelona?

[Sortingfinances]

Is there enough to do to keep us (mum + 16 yr old) busy?
Looking to fly to Spain for a weekend break.
Due to departure airport, and needing to fly for day evening (not day) our destinations are somewhat limited.
1st choice was Seville but the flight times are no good.
Happy to do a city day then a train to somewhere outside to mix it up.
Thanks for any tips!

There is enough to do in both for 2 days.

Have you looked / compared accomodation cost? It can be very expensive in Barcelona.

We have stopped in Santander after / before getting the ferry but not spent a full weekend there. It’s a lovely city though, great food and beautiful coast.

Barcelona has more than enough for two days.

Barcelona definitely; there is more to do there

@cherryassam not looked at accomodation yet! Although happy with a backpackers hostel so shouldn't be tooooo expensive.
Any 'must do' suggestions in Santander?
I'll grab a travel guide from the library too.