Rolo's Riddle

The final treasure you're looking for is high up at the bloody lake where [npc=73282] lives. (Coords: 64.5 - 27.5)

To get there use the Albatross Taxi Service: Move to 33.3 - 55.3 (the entrance of Celestial arena). Once there, check the sky and wait for a [npc=73531] arriving. Hit the bird once then press Escape to stop autoattack. It will pick you up to the sky and transport above the whole isle.
At 64.5 - 27.5 above the Ruby Lake (the reddish tarn on the map) begin to attack your Albatross again. The bird will instantly dive and releases you as you kill it. Swim out of the red pool and go up to the tree. You'll find the final treasure right there.

Video guide:

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• Intended method: http://www.youtube.com/watch?v=JUTksV7Db5o
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• Albatross-free method: http://www.youtube.com/watch?v=wfeW1_WZvT8 - make sure you use [item=104346] instead of freefall if you don't want to look like an egg omelet.
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TomTom

/way 49, 69 - 1st Clue
/way 34, 26 - 2nd Clue
/way 66, 23 - Last Clue

Albatross

/way 35, 56 - Albatross

Chests

/way 26, 64 - Chest
/way 28, 35 - Chest

to get to last clue at the Ruby Lake (66, 26) you can use a [npc=73531] at the celestial grounds (best place to wait is on the right side of the steps 35, 56) just wait for one to be low enough for you to be able to hit it then stop attacking , it will then pick you up and fly you round the island (It's a bit of a slow ride). Attacking it while riding it will make it stop in mid air, you will probably find it easier to knock most of it's hp off before you get to the red lake leaving just enough for 1 or 2 hits. if you haven't been on an [npc=73531] before you will also notice you pass a chest on the peak of one of the hills (26, 64) there is also another chest after the red lake (28, 35) .

note: all clues are by trees,

Here's an albatross-free method:

I went to the north east edge of the isle's coast--close to the red lake--and swam out just far enough to leave the zone into the Time-Lost Waters zone. Fatigue should set in, but you'll have plenty of time to summon a flying mount and get high up in the air (the [spell=145389] buff may not drop, but I was able to fly anyhow). Then fly towards the lake. You'll get dismounted as you re-enter the zone, but you can use some form of slow fall (I used my incredibly handy Goblin Glider) to float the rest of the way in.