Longleat 
This place will keep al of the family busy all day and if you are staying in the area on holiday you may well want to come back for another visit.
First I will start with the safari park which you are able to drive around, or in the peak season are able to go via a bus at an additional charge. You can get out of your car and walk around with the giraffes, and then on to the lions, wolves, tigers etc.
Back in the park area you can visit Longleat house, go and see postman Pat in his village, take a trip on the boats on the lake which has resident seals, visit pet's corner and enjoy a parrot show, go inside Dr. Who's tardis, get lost in the maze ( that is very easy to do, as we found out ) or let the kids go in the adventure playground.
There are plenty of place's to eat and sit down, including several large picnic areas.

Where To
Just off the A36 between Bath and Salisbury and the A362 Between Warminster and Frome.
Opening Times
Safari Park - Open from 1st April to 29th October from 10am to 5pm.
Longleat House - Open from 1st April to 31st December ( excluding Christmas day ) from 11am to 5.30pm
Other Attractions - 1st April to 29th October from 11am to 5.30pm.