Jump to the edge of the wall on the right of the lever. Go to the right, jump above the hole and go behind the bend. Jump to grab the ledge above you, then jump to the back to the wooden platform.
Jump to the left on the horizontal ledge in the wall. Move to the right, use the line to move down and go inside the hole. Leap to the wooden platform and take large first-aid kit. Jump into the niche on the left side - you will move down.
Climb again to the place, from where you decided to jump down into the hole. Where you are there, jump to grab the edge above, jump to the back and grab the line.
Turn right, swing and jump to the stone ledge. Go behind the bend and jump above the hole. Move down - the ladder will break and from now you will have an passage to the rest part of this level.
Go to the unknown corridor. There will be a wooden construction and a bear will attack you, kill him and climb on the wooden platforms on the top of the construction. Take ammo.
Go down and jump to the wooden pillar. Climb on the top of the pillar and jump on the wall with tight ledge. Jump to grab the edge above and jump again on this pillar.
Jump on the next pillar and on the platform. Move down and go to the stairs. Go upstairs, take ammo and turn left.
Jump on the slant platform and in time when you are slipping, jump to grab the tight ledge in the wall. Move to the right and leap to the wooden platform on the left, take ammo.
Jump to the right on the salient crossbar and then leap to the edges. From the bottom jump to the upper, go to the left and behind the bend climb up on the flooring.
Get on the wooden platform and jump to the wall with the ledge. Go to the left, jump to the back on the next wall with ledge. Move quickly to the right and jump down on the floor. Kill bats and take large first-aid kit. Look around.
On the wall on the other side are tight ledges - leap to the upper of them then move down on the lower. Jump to the back into the niche in the wall. Go inside and take another large first-aid kit.
Leave the niche and back on the ledge. Move maximally on the right, jump to the edge above and again on the upper edge. Move to the left. Jump to the back to the ledge, then jump again and you are on the flooring.
Go to the right. Jump to the shelf. Go through the long corridor. The floor will break, you will fall down. Now you are in the lost valley. Really nice place.