I am thinking of places for our upcoming holiday. I have a 7yr, a 3 rd old and a 1 yr old. Together with my parents as well. Where would be a great all-rounded place to visit?

Places in Australia such as Melbourne, Sydney are great for family traveling as you can do self-driving/road trips. There are a lot of sightseeing especially Zoo in Australia. http://travel.usnews.com/Rankings/Best_Family_Vacations_in_Australia_and_The_Pacific/