Am here for 10 days and not sure other than the beach I can do that my children will enjoy? Any suggestions other than theme/water park?
You could check this out - https://www.portaventuraworld.com/en - A special day out perhaps.
Remember you are only 40 minutes from the centre of Barcelona by Trains ,regularly, or L2 Monbus service.
Are you there now? If so, there are human towers at 8 p.m. in Tarragona on Wednesday. Could be an exciting end to an interesting day exploring.
Details here ...
The location is fantastic, too. Note that the square has two names, both Plaça de Santiago Rossinyol and Placa de les Cols.
There's an area on the beach just to the west of the church, trampolines etc. Might be to young for them. My kids are 30 and 27 now so don't look for this type of thing now