When I was a kid in RI I would do something vaguely parkour-ish on the jetties at the beach. I just liked the flowing movements I could make although sometimes my knees got banged up, and some of the rock was sharp.
Now at 30 the past week I have been spending an increasing amount of time climbing trees near my apartment...forgot how much I enjoyed it, and my iguana climbs with me

Plus even though I still need to lose some weight before I seriously jump into pk, I can get up a tree pretty easy.