Barcelona for the day with 11 yo

[florenceandthemac]

We are off to Barcelona this month, just for the day, with our 11 year old. I know Camp Nou isn't done yet but we'll go along to the shop and maybe the cafe, as he is Barca mad.
Does anyone have any must do's/things an 11 year old would enjoy?
Going to do the City Bus Tour, so we can get on and off where we want to, but he also isn't averse to walking (although I appreciate it will be hot!)
Any restaurant recommendations also gratefully received!
Thanks!

My tween was pretty amazed by Casa Battlo and Park Guell, and loved the musical fountain show but not sure you’ll be able to see it in just a day visit.

I second Casa Batllo. DD (15 at the time) was very unimpressed when she learnt that we were going on a tour of it as she’s not a history/art fan but ended up being absolutely amazed by the sheer beauty. It was the highlight of our trip!