Once the level begins, ignore the rats as you move the box towards the wall. Pull the switch, drop down into the hole and enter the main room, again ignoring the rats.

When you emerge in the main room, start off with going to the right by grappling the two hooks on the wall, wall-running, and making your way around the ledges towards the left (first screenshot to the left). Make your way over the horizontal poles to the first movable box (second screenshot to the left).

When you grapple the first hook on the wall, swing to the other side, let go, and then immediately grapple onto the second hook. Swing to the other side and let go to grab the ledge.

Push the first movable box into the pit, make your way down to the ground, kill the crocodile, and then push the box into the water. Having done that, make your way back to the upper platforms by using the ladder and ledges on the wall.

Continue on your way over the horizontal poles and ledges to the alcove on the left, where you will find the second movable box (first screenshot to the left). Push this box into the pit too, and then make your way down to the floor using the ledges on the left side (second screenshot to the left). Push the box into the water, just as you did with the previous box.

Make your way to the opposite side, vault onto the ledge to the left, drop down on the other side and turn the switch to drain the water from the central pit (first screenshot to the left). Then drop down into the drained pit to kill the crocodiles and to push the movable boxes onto the two pressure pads (second screenshot to the left).

On your way out of the pit, it is possible to jump directly from this slope to the ledge above. Run up the slope and when you reach the yellow line on the second screenshot to the left, jump forward, higher up the slope. When Lara lands and turns around to start sliding back down, immediately jump to grab the ledge.

Pull the floating platform towards you, and then make your way back over to the ledge from where you came. Climb up using the cracks and ledges on the wall.

Turn the switch to flood the room. Then, jump into the water and swim to the floating platform you previously positioned. Climb onto it and continue on with the level into the next room.

While the current is carrying you, press the Interact button to swim faster.

Once you reach the lake outside the tomb itself, swim towards the left. When you are above the passage leading to the switch which opens the tomb's gate, surface to grab some air, and then dive down again to make your way to that switch.

Fighting the Centaurs – click here and download the video. Very special thanks to Mona Sax for making it.