Upon entering this area, break through the roots and collect the clues, then jump onto the floating platform. Jump onto the bone rail and shimmy your way underneath the next two platforms while avoid the water rat guards above you. Hop onto the small piece of land and crack open the clue bottle safe. Turn around and jump onto the platform to whack the water rat guard and grab the clues. To get the clues on the other platform, you will need to climb a little higher.
Press on forward and you will approach a fire turtle guard. Watch out for his flaming head, which he throws at you. To reach this guy, destroy the candle on the wooden raft. That will cause it to turn over and lay flat, allowing you to walk across.
Once you get close the guard, clobber him. Grab the clues, then shimmy your way up and around the statue, then continue onto the statue's arm and clobber the spider guard that drops down. Swing over to the suspended wooden boards. Grab the clue on the right before making your way across to grab three more. Avoid the spotlights, as well as the spiked logs, while double-jumping across the walkways in between the wooden boards. From here you can drop down onto the platform with the first guard and take him out and claim the clues. After that, make your way back on top and head to the siren to smash it.
A water rat awaits you ahead. Climb up the rope connected to the chandelier, then walk around to the other side, then drop down and clobber the guard. Grab the clues in the safes in the far corner. Climb back up to the chandelier, then grab the next rope to reach the second chandelier. Below are more clues sitting on top of two snake statues besides the waterfall. Jump down on to them to grab them. Then climb your way back up the rope to get to the top of the waterfall. You will then need to sneak between the lasers around rotating pillar, then hop onto a narrow ledge to grab three more clues ahead. Then head into the large room full of spotlights and floating platforms. While avoiding another fire turtle, leap you way to the siren and bust it, then approach the guard and knock him out.
Spire jump onto the flaming nozzles to reach another platform. Grab the clues, then take out the guards. Break the large candle in the middle to reveal a long vine to leads all the way down to the treasure key. Slide down the vine, but before heading all the way, jump off to the right where the vault is. Grab the last two clues sitting behind it, then crack it by putting in 5-7-1. After claiming you reward, continue sliding down the vine until you reach the treasure key, and it's all yours!