We just went on a great family holiday up the River Murray on a houseboat. The boat slept 12 so we got 4 kids, and 7 adults (including the two nannies) aboard. We went fishing, lit campfires on the banks, went kayaking, and played lots of cards and board games.
I'd love to head out on a holiday that we did when we were kids, gypsy caravans led by clydesdale horses.