L1, TRIANGLE, R2, L2, L2, R2, CIRCLE, L1, You'll hear Lara sigh if you did it right.
PAL version cheat (EURO Machines)
L1, TRIANGLE, L2,R2,R2,L2,CIRCLE,L1

Here are some codes. Go to inventory:

All weapons:L1,tri,R2,L2,L2,R2,circ,L1
Level skip:L2,R2,L1,circ,tri,L1,R2,L2

MORE GYMNASTICS:-  It's not a cheat, but I found a new move that Lara can do. If she is hanging on a ledge, and you press and hold the "walk" (R1) button at the same time you make her climb up (up on d-pad), she will do some gymnastics while climbing.

DIVING MOVE:-  If you want to dive into the water in style then hold down the WALK button and then press SQUARE and finally UP. Keep them held down and Lara will perform a fabulous dive into the water. This move, when performed on land will turn into a roll along the floor.

In the lost valley (on Tomb Raider 1) go to the river and jump in, let it take you down and then shoot the wolves and walk to the cave, go in and kill that wolf, walk past the rock then go to the wall, jump up there and go down to the ground and kill the rapters but don't kill the t-rex , run from him and go to the temple and wait for 30 seconds then run out and wait for him to come and he will bite your head off, it's so cool!

Action Replay Codes

Infinite Air
801ddf020708

Infinite Magnum Ammo
801ddf940032