Level by Drobridski
Walkthrough by Phil Lambeth, with the help of steven17535's video walk
Lara drops down in front of a crawl space. Hop over the barrels in the corner for magnum ammo, go up the steps in the other corner to an outdoor area and climb onto the central building from the back side (using the raised slab). Jump to the roof of the adjacent building, slide and grab and shimmy left over a timed door you'll soon open and pull up onto a flat spot. Go up and to your right for SECRET #1 and pick up the MAGNUMS.
Drop down to the floor and climb back onto the central building. Drop down through the hole in the roof and find a pushblock. Pull it two times, back flip onto a rafter, note the keyhole and go around for a large medipack. Use the block to jump and grab the hole in the roof and pull out. Drop to the floor to see an opening in the nearby ditch that was revealed when you moved the pushblock. Drop down to find a KEY and a timed wall switch. First, push the block further along the ditch so you'll be able to access the keyhole you saw earlier.
Pull the switch, hop back and turn left a bit, jump out of the ditch and weave your way around to the timed door you shimmied over earlier. Find the SHOTGUN and shotgun ammo inside. The timed door re-opens when you approach, allowing you to leave. Climb onto the central building a third time and drop down through the ceiling hole. Use the key to open a door outside.
Exit the building and find the opened door in an alley outside. There's another opened door in the wall next to a ramp, but don't go there yet. On the way to the alley find a small medipack near a mine cart. Be careful as you enter the room off the alley, as there are unmarked flame tiles on the floor. From the purple entrance tile step forward onto the first brown tile, hop diagonally to the left to the next tile, turn left and hop diagonally to the left to the next tile, ignore the medipack on the corner tile ahead, turn right and hop diagonally to your right to the next tile against the wall, turn right and follow the wall to the next adjacent tile, hop diagonally to your right to the last tile and go to the corner hole and drop down.
Follow the short passage to a room with more deadly floor tiles. Jump three slopes in succession to land on a safe ledge and run down the ramp to a lower area. The first order of business is to find a pushblock in the far corner and push it once (to get it into position for later use). Go back and look for an opening leading down to a large storage area with a central pool. Drop down and shoot the baddy, pick up the SHOTGUN he drops and jump into the pool. Find magnum ammo at the bottom and pull back out.
Find the lower pushblock and move it once to form a bridge so you can climb onto the crates and pull the higher pushblock and push it in the same direction where the lower pushblock was. Hop down to the floor and find a KEY in the corner, then move the lower pushblock against the near wall and toward those yellow and black stripes on the floor. Get on the lower pushblock and take a running jump to grab the higher crate near the corner. Pull up for SECRET #2 and pick up the shotgun ammo.
Drop back to the floor and move the lower pushblock all the way back to its original position and push it into the opening between the crates to form a bridge. Pull the higher pushblock onto the lower pushblock, get up to find a still higher third pushblock (the one you moved earlier). Move it onto the other two pushblocks, so that now you have access to a wall switch that opens a door somewhere.
Get down to the floor and go up the wide ramp to the beginning outdoor area. When you get there, loop around right into the opened door you ignored earlier. Shoot the baddy, take his MAGNUMS, pick up the small medipack on the makeshift bed and use the key to open the nearby door. Shoot another baddy inside, grab a spare set of MAGNUMS and enter the adjacent room. You'll hear the sound of a trap door opening in the room behind you. Get past the electric cart (you'll probably have to run over a breaktile to do so) to find a wall switch. Pull it down and go back to find the opened ceiling trap door in the previous room. Pull up inside, and when you find and pick up the FUSE a door opens somewhere.
Get down, exit to the outdoor area and turn right to go through the opening near the boat to the room where you began the level. Hop down to find the opened door ahead, go on through to an outdoor area where you'll hit the finish trigger if you go as far as the parked motorboat. For the final secret, go left just inside the entrance, step backwards off the pier's edge to drop into the water and find a gold plaque for SECRET #3. Turn around and swim under the motorboat to end the level.