The wallaby pictured above is actually at Whipsnade Zoo, but you may be surprised to hear that they can be found living in the wild in the UK too in a few particular places. See the Feral Populations sections of the Wikipedia page on Wallabies for the details of the populations that have come and gone in a few choice spots.

Actually the Whipsnade wallabies are generally allowed to roam freely within the extensive parkland grounds of the zoo along with other animals like Muntjac deer and Mara, which I blogged on previously. It's easy to see how they could live quite happily in the wild in the UK, being bouncier deer in many respects.