Penguin Agility Course
After completing your runescape accounts s the Cold War Quest, you'll have access to the Penguin Agility Course which requires 30 Agility and a Penguin Suit disguise,so you need to power leveling your agility first.
The Penguin Agility Course is located on the Iceberg north of the Penguin Outpost. To get here, head to Rellekka, either by walking, or by using your Enchanted Lyre teleport. Take the boat from Rellekka to the Iceberg, and then head to the avalanche to the northwest. To the west is a room; follow the corridor to the Penguin Agility Course.
Penguin Agility Course
Obstacle Agility Experience
Climb Platform 55
Platform Jumps 80
4 Icicle Gates 40
Ice Slope 180
Agility Bonus 65
Total 540
Barbarian Outpost Course
After reaching level 35 Agility, you'll have the ability to enter the Barbarian Outpost training area located northeast of the Tree Gnome Stronghold. But before entering, you'll need to complete the Alfred Grimhand Barcrawl. Once you complete it, you can enter the area, climb through the Pipe and begin to train your Agility!
For fully completing the course, you'll receive 117xp, along with a 46.2xp bonus, for a total of 163.2 Agility experience. Be warned however, that the obstacles can be failed and you'll take damage, so it's a good idea to bring some food with you. Should you fail an obstacle, make sure to try it again so that you can receive the full amount of experience.
First, swing on the Rope Swing and then cross the log. Climb up the Net, cross the Ledge and climb over the 3 Low Walls.
Barbarian Outpost
Obstacle Agility Experience
Pipe 10
Rope Swing 22
Log 13.7
Net 8.2
Balancing Ledge 22
3 Low Walls 41.1
Bonus 46.2
Total 163.2
Extended Barbarian Course
After reaching level 90 agility you have the option to use the new extended area for more experience. To start the extended portion, first swing on the rope swing, walk-across the log balance, and run up the wall next to the obstacle. To run up the wall you need 90 agility.
The course gives 725.7 experience and you can fail on all parts of the course. To compete the course you must swing-on the rope, walk-across the log balance, and run-up the wall. Then you must spring the device, walk across the balance beam to the next roof, jump to the next rof, and slide down,when you finish this course you ll get some runescape gold.
Brimhaven Agility Arena
The Agility Arena located in Brimhaven is a great place to train once you have level 40 Agility. It's a big place, and you'll get lots of experience. To some, the Agility Arena is a fun way to train, while it's boring to others. Remember, the arena is supposed to be challenging and you're likely to take quite a bit of damage here.
You'll want to bring several things, including Boots of Lightness, about 1,000gp, Cakes, and teleportation items (Runes, amulets). The reason for bringing Cakes rather than something like Lobsters is the fact that the more hitpoints you have, the more damage you'll take. Staying under 20 hits will only cause the obstacles to hit you for 2 points.
Once you have everything, talk to Cap'n Izzy No Beard located in a house north of the entrance to Brimhaven on Karamja Island. Pay him 200gp to enter, and then climb down the ladder into the arena.