family holidays for little ones in UK

hey ladies,

my son is almost 3 and my daughter is almost 3 months, were looking to go away in the summer for a week but im not fond of flying myself and when we went abroad when my son was 1 he cried and screamed on the plane the whole way there and back. so i dont really feel comfortable going abroad again until my daughter is a little older.

obviously we want a fun filled family holiday so can anyone recommend somewhere nice in the UK?

i know theres places like butlins but thats not really our cup of tea, so any recommendations from you mums out there?