The first thing you see when you begin the level is another dreaded mutant statue. He won't awaken as you approach, though, so you can safely pick up the large medipack and two sets of Uzi clips from the ground. Go past him into the next room, with weapons drawn to face a mutant that does awaken. The lever in the alcove at the opposite end to the entrance does nothing but awaken the first mutant, so don't bother unless you want the kill.
There is another lever on the wall to the right of the doorway as you enter, in the alcove. Pulling this opens the exit door, but also awakens two more mutants. I recommend using the automatic pistols or the Uzis and staying as mobile as possible to deal with them. It's not as difficult as you may think to destroy them. Just try not to get trapped in a corner by one like I did! :-(
Enter the next room with the pillars with weapons drawn, and keep an eye on Lara's health bar. There are three pairs of knife-throwers in here, each pair emerging as you pass three pillars. Take one pair at a time, keeping mobile, possibly jumping back into the previous room where you will have plenty of room to jump about. When they're dead, pick up the goodies that they drop: large medipack, small medipack, six sets of Uzi clips and a Mystic Plaque.
Use the plaque to open the large, iron gates that lead to the dragon's lair, but please approach with caution. Enter the lair, and save your game once you slide down the slope. Different walkthroughs give many different ways to combat the dragon, but there is only one reletively easy way.
There are ten sets of Uzi clips and two large medipacks at various places under the floor, which is filled with water. However, if you decide you want or need them, make sure you keep to the perimeter, as approaching the center of the room above or below it, awakens Bartoli and he changes dramatically into a huge dragon!
You can take your chances and dive in to retrieve the goodies if you want all of the pickups, then use your Uzis to keep relatively mobile while you fire at the dragon, but if you fall into the water, it takes some time to climb out and he will be on you, so don't dawdle! After about 300 rounds with the Uzis he should fall. However, here's how I do it:
There are several pillars surrounding Bartoli, who is lying on a pedestal. There is a pillar just before Bartioli in the center of the room. Approach this carefully from the left, keeping behind the pillar at all times. Bartioli will transform as you approach, but as long as you stay behind that pillar you will be safe(ish!). Take a step or two back so Lara can target the dragon with her grenade launcher, and after about twelve hits the dragon will fall. Save your game immediately it begins to fall, so you don't have to do it all again. Run to the dragon's belly, where there is a red mark which holds a dagger. Pull it out by pressing 'action' as close to it as you can. If Lara doesn't pull it out, jump once into the air to get as close to it as possible, and make sure her right hand is near it. Once the dagger is pulled out, the dragon dies!
However, you are still not safe, as the room begins to collapse around you, so don't dawdle...run towards the exit doors that have now conveniently opened, and don't stop! Just keep running until you hit the end of the level.
A cut scene shows Lara being knocked to the ground, but she soon recovers and heads for home. :-)
If you missed anything while playing the PC version, here is the savegame file with all kills, pickups and secrets.