What is this sport called?

Ok, so there’s this sport that involves running through developed areas and doing random physical stuff (oh, grow up). And you pretty much go all over a city, and treat the landscape as sort of an outdoor gym, and physically exert yourself in it. I KNOW that this is a real sport, because I watched a program on it, but I’m totally blanking on the name. Help me out?

It’s called Parkour or free running you run and jump around cities and climb up walls and other surfaces it looks very challenging but fun.