Used to love it when I was in my 20's.
Climbed the west wall of the middle sister of the three sisters in the blue mountains in the rain when it was still legal to do so, then absailed down the other side, top to bottom, was a great day.
Done plenty of shorter climbs, mainly in the blue mountains.
Have also absailed down the side of several buildings in the CBD of Sydney all for work when I was younger, as well as Waverley radio tower, 110meters from memory.
EDIT:
Since you mentioned back packing, back packed around Thailand in the early 90's, including tracking for a week through the Golden triangle on foot and elephant back as well as home build bamboo rafts and camping out in the jungle. Included riding a motor bike around a large part of the country over a few weeks. The leanest I ever was, not an ounce of body fat, abs and muscle definition I can only dream about these days.