Its an outdoor activity called "Flying Fox", where you are harnessed and attached on wire rope with the help of pulley from higher place to the lower ground.

Depending on you body weight as it is designed to enable a user propelled by gravity, it could feels like you are riding the wind so fast, it pumps your Adrenalin, urged you to just scream....

Its a fun as well as thrill at the same time. Good thing is, its usually very safe.