MIL has foolishly offered to mind the 3 DC so me & DH can go away for a few days
Our nearest airport is Southend (aka London Southend!) and we can fly to Barcelona. Neither of is has ever been there and people say it's fun/worth going to.
We're looking at the first week in October possibly.
Budget - ideally as cheap as poss, but, must be a nice hotel. I am not spending my DC-free time in any fleapit 
Where is good, which sites to search, etc? I get overwhelmed when I start looking.