Here's my walkthrough, with all four secrets. Thanks to Turbo for pointing out two of them.

The level starts with Lara sliding down a ramp. First thing to do is to go and collect Secret #1. Run to the far left corner of the room, in the space between the grey stone pillar and the stone wall. Turn to the left wall to discover a ledge that leads to the secret : a box of shotgun shells, Magnum clips and a big medipack. Go back to the main room and run to the right and vault onto the ledge there. Pull up to the slope and slide, jumping to reach the flat surface ahead. Pick up a small medipack and a box of shotgun shells.

After getting the goodies notice the area on the right with the opening high above. Climb the column and enter a room full of spikes. Climb the ledge on the right. The moment you do this, darts start flying out of the walls. Go as close to the right and climb the upper ledge. Time a forward roll to avoid the darts, drop and shimmy all the way to the right to the switch. It opens the door in the room Lara initially started. I don’t know if I triggered a bug or if this is the way the game just plays, but if you save and load right after pulling the switch, the darts stop for long enough for you to run safely to the opening, thus saving some time. No matter which way you choose, go back to the main room and enter the newly opened door. There are two differently colored tiles and a closed door. The first tile opens the door and the second closes it, so make sure to jump over the tile with the circular depiction on it.

The next room has a bunch of slopes that can lead Lara to her death if you’re not careful. Depending on the time you slide, either jump to land on the ledge or jump and grab to pull up. Jump forward to avoid another slope. Vault onto a differently- colored ledge that opens the door up ahead. Once again, beware of the inclining ledge ahead, as it closes the door. That’s why take a running jump and grab the edge. Go through the door and draw weapons, as there are four gorillas that await you. Two of them come at you immediately and the other two hide in the far right corner of the room. After they’re dead, vault onto the ledge to the right of the door and climb up to grab one small medipack, a box of shotgun shells and the shotgun. Drop to the floor and go to the different tile in the centre of the room, which opens the door. The problem is that it closes a second or so after Lara steps off of it. Go to the wall facing the door. Position Lara so that she faces the rightmost side of the tile and take four steps forward. Press jump and forward and she’ll land on the edge of the tile but keep running and after three more steps press jump again. Lara will pass and the door will slam behind you.

Run to the far- left side of the room and vault onto the edge. Turn right and climb the pillar. Notice the edge on the right that’s about the same height as the one you’re standing on. Position Lara so that she’s barely seeing it and take a running jump to land on it. From there jump on the flat pillar on the right and then to the one diagonally to the left. Get as far back and to the right as possible and jump forward. Vault onto the next ledge, drop and shimmy all the way to the right. Pull up and roll, so that Lara’s next to the wall. Take a running jump to the slope ahead and Lara will land and slide backwards. Grab the edge and shimmy to the right till you can climb up. Turn right and take a running jump to the next ledge. After you land, walk to the far right edge and position Lara, so that she’s looking at the middle part of the sheltered ledge. Press jump and grab simultaneously, otherwise she’ll hit her head and fall to her death. Shimmy to the right and climb up. Walk to the end of the pillar and jump to the edge on the right. Turn around and look for the opening up ahead. Position Lara so that she’ll land at the near end of the slope up ahead. Press jump and keep it pressed because Lara will bounce off the slope right into the opening.

The first thing you see in this next room are the two stone centaurs guarding the door and the different tile. Stepping on the tile opens the door but the moment Lara gets off, the door closes. Ignore this for now, you’ll come back here later. Head for the room on the right, pistols drawn, because there are four angry gorillas. Back flip into the previous room and take care of them. Reenter and notice the different tiles on the floor. You need to step on five of them in order to open the door. Four of them are pretty obvious and the fifth is situated near the far- left corner of the room. Climb to the top and enter the door. Stay in the opening and shoot at Pierre. Not long after his trademark lions, four of them, to be exact, will go after Lara. The easiest way to get rid of them is to fall to the floor and shoot while jumping up and down. After they’re all dead, climb back up to do some exploring.

Jump to the platform where Pierre was standing and enter the passage on the left. Go to the right, then to the left three times and you’ll be rewarded with a big medipack. Roll and continue forward. Lara will reach dead end passage. Go to the left and pick up two boxes of shotgun shell. Then head for the right side of the passage. Notice the different tile. Run toward it to drop into Secret #2: the Magnums and two Magnum clips. The Magnums are in the right corner and the clips- in the left. Climb back out and traverse back to the main room. Go up the stairs and head left. Continue till you reach a block, which you need to get on top of. Climb the rest of the blocks to come face in face with a collapsible tile, swinging blade combo that might need a couple of tries. After you’re past that, you’ll be greeted by some hungry lions. Don’t stand on the top because the lions can reach you but rather take a running jump to the block with the vase on your left. From there you can safely kill all four of them.

This room holds nothing of interest, so move on to the next room. In the far- right corner there is an opening to another room, so take a running jump and grab to reach it. Run to the end and take a running jump and grab to pull up onto the next platform. Repeat this two more times and them run to the end of this platform. Safety drop to the platform below and to the one under it, pressing roll to avoid any damage. Afterwards aim for the ledge on the left, taking a running jump to reach it. Go to its end, face backwards and press jump, grabbing the edge. Release and immediately press grab again, or Lara will fall to her death. Pull up and then follow the blocks to the floor.

Go to the opening on the left and look at the slope. There’s a boulder there to ready to flatten you if you’re not careful. Go and position Lara so that she’s facing the wall, as much to the right as possible, without actually stepping on the slope. Side flip to the right twice and back flip once to land in a very convenient alcove. After the boulder’s passed, drop back on the slope and run to the top. Once again, align Lara as before and side flip to the right once and back flip, to land in another alcove. Then go to the top and jump and pull up into another room. You should be close to the light- colored slope with the boulder. Run along its length and stop when you reach the tall pillar on your right. Press the forward button once to land into a room, containing Secret #3. Position Lara, so that she’s facing to the right and drop to a stone block that was invisible to you. Use the blocks to drop to the floor and collect three small medipacks scattered on the floor. Climb back up to the previous room.

Head up the slope. Look to the right and stop right before the area where the stone pillar on the right begins. Take a step back and hop forward. Side flip to the right to avoid the boulder. Head back up the slope and turn to face the next one. Once again, keep in mind where the stone pillar is. Stop right at the end of its equivalent position and turn to the ledge to the right of the slope. Jump forward to land on it. The boulder will pass by harmlessly. Go to the top and face right. Take a running jump and grab the edge. Repeat with the following gap, too.

Pull up into the opening in the ceiling into a room infested by rats. Throughout the room there are twelve of them. Apart from startling you, they’re no threat. In the process of killing the rodents, you should have noticed some stone blocks, leading to a new room. Pass through it into the other room, being careful of the holes in the floor. The second room continues into a passage. Jump over the hole on the way and follow the corridor, which opens up into a room. Walk to the edge of the block and face the pillar with the collapsible tile above it. Jump and grab it, then pull up, to cause the tiles to drop. The camera angle will change and you’ll see that the second tile debris have fallen on the trigger tile in the room with the centaurs. Head back to the second room and safety drop from the hole in the floor onto the platform below. You’re back in the room after the swinging blades. Climb back up and near the edge of the entrance. Safety drop below. Lara will lose some blood from the fall. Go back into the room with the centaurs to find that the door is now permanently open.

Enter with your pistols drawn and start shooting at Pierre, who is on your right. After he’s gone, assuming that you’re at the gates again, turn right and follow the passage. When you reach the intersection, turn right once more and you’ll end up on a tile depicting a flying horse. Now there’s a bottomless pit in front of you and the other side is too far to reach. Bugger, huh? Well, no. Bravely take a running jump forward and collapsible tiles will magically appear under your feet, keep running and you’ll safely enter the next room.

Run to the room on the left and head for the big grey save crystal that’s actually transporter. Lara will go to a new room from there. Turn to the right and take a running jump or dive onto the next platform. Use the blocks to drop to the floor. Look around and spot the opening in the wall. In this passage there are those nasty teeth slammers whose sounds give me Goosebumps. The best way to deal with them is to approach them and roll through when they are ľ open.

This next bit is really refreshing. Upon entering the room, you see a section that looks like liquefied air. Anyway, choose either slope and go to the end. Jump and pull up to slide on the collapsible tile. If you’ve chosen the left slope, upon landing execute a left side flip to splash into the water. Swim to the top far- right corner to grab a key from the pillar. Turn around and quickly swim to the other far corner of the room to find a passage near the ceiling that leads to Secret #4: the Uzis and an item that looks like a section of the wall. Jump up to go back underwater and swim to the main room. Head back to the yellow pillar back at the “entrance” and pick up a large medipack. Face the room with the spikes and gently start pressing the Alt button. Don’t press it too hard, or Lara will land on the spikes. She will lose some blood upon landing. Now take a running jump to grab the edge of the pit. Backtrack to the room in which you were transported and locate another transporter to go back to the main room with the keyhole.

Go back to the room with the door and use the key. Enter this new room. Notice the switch on the left side of you. Don’t use it yet. Walk to the other side of the slope and face its right end. Take a step back and then hop back. The centaurs will come to life. Immediately jump forward and slide to the bottom. Run clean on the door and side flip to the left. Slide to the bottom and face the slope. Wait until all of the centaurs are out of the room and head towards you and jump over the slope. Swerve right and run to the switch. The doors will close. If you’re fast enough, none of the centaurs should be in. Use the switch to let only one centaur in and battle them one by one. When you’re done, go and pick the key from the pedestal to finish the level.