Skill - Agility

Agility is one of the 18 "skilling" skills. In order to do agility, you must go to ::agility, which will teleport you to the Gnome Stronghold Agility Course.

Every time you complete the course, properly, you should get 40,800 experience, which means for 99, you will need to run the course 320 times. You should be able to complete the course in no more than 30 seconds, which will take you around 9,600 seconds to do. Or, 160 minutes, or nearly 2 hours and 40 minutes to achieve 99.