Glutton for Fiery Punishment

For those confused, the site is the island in the top of Azshara that has no name with it just north-east of Darnassian Base Camp. On the South-West of that island is a portal that leads to more that get you up the mountain. Don't stop on the way up or a frost ball will come down and blow up next to you throwing you down the hill.

When you get to the top, you have to click on a crystal, it will open the portal in the circle, and then you have to click the portal to enter the instance you picked. I thought that you just had to click the crystal and you got in, but you do have to then click on the portal.

HOW TO:
Shadow: Click the crystal to start it and then lead the Shadows into the platforms. The platforms will go away with each shadow that it takes, but more will show up as you go along. You can mount which makes it a lot easier.

Fire: A ball will travel from platforms that did have fire on them to other platforms. 2 will not get the balls and so will not catch on fire the next cycle. You need to run to these and /dance.

Ice: Run around a get the SMALL ice orbs that show up. Do not get hit by the frost that is going around the large orbs. Do not walk over the blue platforms or an ice spike will come out of the ground and throw you up in the air. I found the easiest is to run around the outside and hide in the pockets at the edges to wait for the frost to pass. take your time and you can get 20 in a row. Do not worry about the counter that shows up. When it hits 20 it will reset, but if it is at 15 when you get hit and then you do 20 without getting hit you can get the achievement with the counter saying 15.

Hope this helps.

Good news for Alliance players...I just got all three achievements. The three trial zones are as follows:

The Trial of Fire: 33, 23.5
The Trial of Frost: 62.2, 21.1
The Trial of Shadow: 31.1, 26.8

...then just start doing the trial. No quest, nothing, just start playing. I turned on the tracking for each achievement as I was doing them, and completed all three in about ten minutes flat. Note that to start the Shadow trial, you have to click a crystal at the trial area (it's marked); the other two, just do it.

Knowing the locations as I do now, I'd probably start at the Shadow zone and work my way east.

Also, not knowing that I didn't need to use the portal to get to the zones, I went back to the island with the crystals each time and clicked on the corresponding one before going to each trial zone. So if they don't work for you, try that.

Have fun!

Get this achievement by doing this quest http://www.wowhead.com/quest=14300.