Where is fun? 2 hours max from Cardiff

Mendip Activity Centre offers everything from frisbee golf to kayaking, tobogganing to bushcraft and raft building to skiing or snowboarding. It's not too far from Longleat Safari Park. Not only does Longleat have the enclosures to drive through but several other animal exhibits including penguin island and walk though monkey and parrot enclosures. There's also a boat cruise to an island of gorillas, a big hedge maze, railway, adventure castle playground, bat cave, petting zoo and small aquarium.
In the same area you could visit Cheddar Gorge. Kids of all ages love the challenge of climbing the 274 steps up the side of the Gorge, then 48 more to the top of the Lookout Tower! There are 4 landing stages for those who prefer a slower pace. There are also caves to explore at Cheddar. TheCrystal Quest is a dramatic story kids can follow through the cave beyond Cox's, where character figures and props plus strobe and add to the adventure! Plus in the Museum of Pre-History kids can try their hand at cave painting, flint knapping and fire making.