Tomb Raider Underworld Strategy Guide 34: Southern Mexico, Part 14
What you need to do is face the statue on one of the daises to the right or left, and grapple its head. Then walk around it, and pull on your grapple. The head will open up all the way, and you can jump onto the hammer thing like a ledge, then jump up to get to another room.
You will then grab one of the gauntlets. Go back to the gear room on the left side using the same set of ledges that you used last time. Pull on the purple marked area, and you will find a new room. Climb up the ladder and jump off when you get high enough.
Now, you will want to follow the hall until you come to some ledges. You will first want to turn around in this room, or you might miss the Tenth Treasure.
Jump up two ledges to an edge, then jump across to another edge. Jump up a few ledges, then backwards jump to more ledges. Jump up to more ledges, and then stand to jump to another one. Backwards jump and climb up more ledges. The next ledges are on the side of the wall, so jump to them. After about three jumps, shimmy to the right and stand. Jump up again about two more jumps on the walls.
You will soon be able to pull yourself up. You should know where you are: the icy area where you got the gem head. Go to the only open door in this area, and slide to the next level down. Run back to the Mayan trap room.
There is only one thing that you can do from here. You may have noticed a long stairwell that leads way up to the top. You need to take your motorcycle and go up this stairwell, accelerating at the gap so you can go over.
Get off the bike at the top, where you will see a door with a tile in the corner. The gauntlet allows you to interact with the tile, so you can move it, and the door will follow. Get back on the bike and go out the door.
From here, it is a series of jumps and pits. The first is right down the center, accelerate, and you will make it. The second and third, just keep to the left and right. On the fourth, there is a little bump on the left that allows you to sail across. Go to maximum acceleration on the last one. This will get you to the next area, and end the level.
