Star Wars Jedi Knight: Dark Forces II/Valley of the Jedi

Level Nineteen: The Valley of the Jedi
''Jerec's troops have excavated deep into the surrounding chambers that lead into the Valley of the Jedi. Make your way through the Imperial excavation to the Valley core.''

Mission Objective: Make your way to the excavation below the Imperial superstructure.
Go through the hallway and up the ramp into a room, then go through the door. Go through the downward-sloping hallway and round the corner to an elevator shaft.

Secret Area 1/8: Ride the lift down one stop and jump up onto the ledge across from the elevator.

Ride the lift to the bottom and jump up onto the top of the small building in the center of the area.

Secret Area 2/8: Jump up onto the ledge directly across from the elevator.

Secret Area 3/8: The outside walls of the infrastructure are anchored to the walls of the earth with horizontal beams. The third secret area is the highest beam.

Secret Area 4/8: Look up from the highest beam; the secret area is in the alcove above.

Destroy the grate in the roof of the building and drop inside, then ride the lift down.

Secret Area 5/8: This secret area is beneath the lift.

Take the lift at the other end of the room, and crouch under the supports to emerge at the drilling site.

Mission Objective: Manipulate the ancient doors to open a passage to the Imperial troops guarding the valley core.
Corkscrew down around the site to the tip of the drill. Hop down the hole in the ground into the burial grounds, and go through the hallway. Meander through hallways and rooms to the area pictured.

Secret Area 6/8: Instead of turning left to the area pictured, turn right and blow up the wall.

Go through the room and enter the dark area. Go through the tunnel ahead and down into the next room.

Secret Area 7/8: Blow up the wall to the left of the metal ramp.

Head up the ramp and through the tunnels to come upon a large, dark room with dismembered Stormtroopers and two Kell Dragons. One of them is skulking around a hole in the floor; either kill it or run around it and drop down into the tunnel. Go through the tunnel and up the slopes to a room lined with ledges. Get down to the floor and go through the next room and down the slope to the next hallway.

Mission Objective: Find an alternate passage to the Valley of the Jedi entrance.
There is a large switch on the left wall that opens the door just ahead. Hit the switch until the door is opened all the way. Proceed through the hallway to the next door. This time, open it all the way and then hit the switch again to close it; run through before it does. Jump up into the sloped hallway to the left of the next room and follow it across the door weights.

Secret Area 8/8: After crossing the first set of door weights and up to the right, there is a weak wall to blow open.

At the very end of the tunnels, there is an area that drops down into a spacious room with cargo crates.

Mission Objective: Fight your way through the blast doors to the Valley of the Jedi burial chamber.
Go through the large door to the left and take down the AT-ST. Kill the commander to get the red key, and use it to open the locked door to the Valley core.