Top CL for walking a dog off the lead

We are located in Malmesbury North Wiltshire. We would like to know if anyone has some recommendations for cl's within a one and a half hour radius from here where we could take our little dog and walk her off the lead from the site. She is a small border collie jack russel cross and never tires out!! so a LONG walk would be somewhere between 2-5 hours.(culminating in a pub would be ideal!!) If someone has any experiences we would really appreciate sharing.