SUMMIT FOREST CAVE
With all optional things done in this zone, head for the waypoint to the east. Move over the bridge, destroy the door with a rope arrow and proceed through the cave until you reach an area with caged wolfs. Climb the nearby ladder, use a rope arrow to swing the deer against the pole, then immediately leap over to the pole, using it to reach the climbable wall. [100 XP].
Summit Forest last GPS cache.
You'll find some [SALVAGE x2] and [SALVAGE BAGS x2] here. A [GPS CACHE] can be found among the bones near the doorway. Proceed and Lara will slide down; get a good grip, then proceed through the linear path, following the bats to the right (which is the direction of the exit, there's nothing else in the cave).
Outside, slide down the rope and you'll be contacted by Alex. [900 XP]. Slide down two ropes, look for some [SHOTGUN SHELLS], then jump on one of the cages (but wait for it to come really close first, obviously). [100 XP].
The gondola stops soon enough, so shoot an arrow into the rope on the nearby platform and slide down. There's [HANDGUN AMMO], [RIFLE AMMO] and [SHOTGUN SHELLS] near one of the corners. Climb the yellow ladder on the other corner and slide down the rope; a major firefight commences. You can find [RIFLE AMMO] close to your starting position. The fight isn't too difficult; make use of the explosives around the area and quickly take out your foes one by one.
Soon enough a scene plays, after which you'll need to climb up and sidewards (right) until another scene takes place. Leap over the gap, then (automatically) slide down the ropes. You'll have to push B or Square at the right time as you approach a second rope below (you'll have to do this a second time; the game slows down when it's time to press the button). As the last rope ends, you'll have to press B or Square again to make Lara slide down. Quickly shoot the barricade with your shotgun and jump to grab the pole. Lara automatically grabs the next rope, but you'll have to press B or Square again as she approaches the next one. As the rope ends, push the button one more time at the right moment. Shoot out the barricades in the river with your shotgun to end the ride.
Make your way through the crack at the end of the path to reach the next area.