first, you need a moutain, like this one, second, be sure to run when you jump, i showed you what happen if you walk at the first demonstration. In the same area, you can go into water and run after slaugterfish, if you can find 3 slaugterfish, or 4 if your lucky, you can train all type of armor by letting them hit you. Be sure to be low level and have very low agility, or there's some chance they won't be able to hit you otherwhise.
