After your enter the next location, go left, where you have last seen the character in the red cape. Climb up the stairs and approach the metal key. Collect it, approach the wall and use it to open the way ahead. You will reach a big Coliseum. In the location, there also is, among others, a sphinx and two passages to the next locations.
First, take the passage on the left and climb up the stairs. Move a bit ahead and go towards the tower. After a while, the bridge will crumble behind you. Climb up the stairs and you will run into a hole in the ground, after a while. Jump down. Approach the ledge. Lower yourself and jump over to the other side. Climb up over the roots and you will reach a puzzle with figurines.
Activate the figurine next to the water and climb the platform quickly. In a moment, the platform goes up. From here, jump over to the other side, grab onto the ledge and enter a new location. Move the orb on the pedestal closer to the figurine and activate it with your voice. Once you have revealed the passage, move the column to the marked button on the ground and use your character's voice again. Jump onto the platform going up and walk through the newly-revealed passage.
You will reveal a passage to the next figurine - you simply have to jump onto it and climb over the golden ledges. Then, push off towards the projecting fragment of the floor and walk through the passage. Move the stone block with the orb to the right, so that it reaches the figurine in the distance. Use your voice and you will reveal another figurine above the passage. Move the orb left and activate it. The column will rocket up.
Jump onto the elevated column and climb up. Push off to reach the projecting stone fragment and go outside across the window. Lower yourself, move right along the edge and climb up over the roots. Follow the steps up, use the ledge again and climb up to the very top. Approach the big orb, shout and there will appear a red tree in the Coliseum.
Jump down and head towards the fox. Keep running down and towards the tree. At the foot of the tree, you will find the first key fragment. Place it inside the sphinx and go through the next passage to the next location.