[Help] More interesting ways to exercise a dog besides walking/fetch for extended periods of time?

A close family friend is having their dog boarded and they asked me to exercise him. He is a very high energy Australian cattle dog and while he likes walking and fetch, it's hard walking in loops around a single office park that is by the vet. I know he would like something more stimulating, what is something I can do that is on leash (or in a small gate off leash) that would be more interesting for both of us? via /r/dogs http://ift.tt/2qE8Ogo