Once you reach the new area, there are entrances at the top and the bottom of the structure to the north. Since the top gate is locked, enter the bottom gate.
There is an arena-like structure once you inside, jump down the bottom of the arena and several enemies will spawn. Trico will not be able to move at first because of one soldier having a glass eye shield. Charge into that guard first so that Trico will be able to move and defeat the enemies.
After Trico defeat the guards, call the creature to turn the gears of the giant lever at the center of two gates. There is a wheelbarrow inside the room to the left, pull the carriage out then place it in the center of the light. Call Trico and prepared to be catapulted up towards the direction of the light.
Grab onto the ledge and proceed to the second level. There are three levers in the area, so activate those first before calling Trico outside one of the opened gates.
The second floor
Call Trico and he will jump over to the second floor. Go outside one of the opened gates and there will be a roof to the right that you can walk on to reach a new area.
Once you’re in the new path, proceed to climb on top of the creature once it reaches the center of the area and it will jump towards the next path.
Swimming with Trico
After reaching the end of the path, you will see a barrel. Give the barrel to Trico and climb on top of the creature. The creature will leap on top the big wall to the right.
Jump down the pool of water below and swim under the gate to the left. Activate the lever located in the area and the gate behind you will open. Trico will jump down and swim towards the aisle to the right.
Dive deeper in the pool of water and Trico will follow you underwater. Grab onto Trico as it swims to proceed to the next area.
To the south of the second area, there is a gate similar to the one found in the first area, so just swim underneath it to go inside. There is no ladder that can help the boy reach the lever in the area, but in order to reach it, call Trico and it will jump down the water, causing a big wave that will help elevate the boy to reach the ledge.
Grab onto the ledge and climb up until you reach the lever. Activate the lever and the gate behind you will open. Dive deeper in the water and grab onto Trico once it swims underwater. A cutscene will occur shortly after you grab onto Trico.
Once the boy wakes up, move to the circle to the right and it will start glowing. A cage-like elevator will come down, so take the elevator to proceed to the upper level.
Head to the railings at the back to the right and walk on it until you reach another structure. Climb the platforms to the right until you reach a chain. Climb up the chain then proceed to climb the patch of grass as well.
Once you reach the top, you will see the tail of the evil creature who looks like Trio. Climb on the tail and jump to the wooden branch on the right. Head towards the tree and climb the patches of grass until you reach a stone platform.
Move forward towards the entrance of the ruins. The head of the evil creature will sometimes poke out of the holes in the ruins, but use its head to jump over the platforms. Time your jumps when it puts its head on a hole, jump over the top of its head then proceed towards the next area.
After going out of the ruins, head towards the cage-like elevator. Once you’re inside the elevator, the creature will pull you down. The boy is now trapped inside the cage.
Wait until the creature flees the area. A cutscene will occur, and Trico will dig a hole above and jumps down to where you are. Use the cage like a hamster ball and run to the left. Trico will help you get over the stone floor. Proceed to the next path.