Hi, any recommendations for places/areas to stay in Barcelona with 3 children. Thanks 
I stayed at the Hotel Arts with my children about ten years ago. It’s by the beach and has a swimming pool, which means between all the sight seeing you can have some real downtime. There’s a kids activity programme too.
For something more in the centre, Grand Hotel Central is great - a rooftop pool and sunrise rooftop yoga - but also interconnecting rooms and suites with sofabeds
If you want more independence, consider an aparthotel - this one is centrally located and has all the amenities
I can vouch for the grand central hotel as above, the rooftop infinity pool is amazing, and the location is great.