Here is a breakdown of the locations of all the keys and pieces of the Chronosceptor that you can find in Turok. While i'm sure this will be quite helpful, my advice to you is to not use it. This is an outstanding game, and one of the best parts of the game is exploring the levels; however, i know what it feels like to be stuck so i'm giving you the answers anyway. Just don't use them as a crutch. Also, please note that i've labeled the keys by where they go in your inventory, not in the order that you get them.
Second Level 2 Key: Along the pathway to the left of the first key you'll see a vine-covered wall to your left (your map will show the location). Climb up and you've got the second level 2 key.
Third Level 2 Key: Take the second route to the right of where you found the first key, and you'll eventually come to an island with two soldiers and the third key for level 2.
First Level 3 Key: This key is located just south of the teleporter that takes you to the unchartable maze of green obelisks.
Second Level 3 Key and the Chronosceptor Piece: Inside the unchartable maze of green obelisks you'll find the second level 3 key as well as the first piece of the Chronosceptor. Look carefully.
Third Level 3 Key: After you fall into the dry well you'll come across the first level 3 key right before the teleporter.
Second Level 4 Key: You can see this key across a chasm in the cliff face. To get to it you must go to the left and fall down right next to the treetop that is sticking up from over the side. Follow the cavern and you'll find the second level 4 key.
First Level 5 Key: Take the path to the right of the level exit transporter and you'll find the first level 5 key.
Second Chronosceptor Piece: If you take a hard left just past the temple with the three soldiers that drop from the sky (there are also two statues holding flames), you'll find a climbable wall. Follow the passage until you come to a cliff. Use your map to locate the two platforms and jump down. The Chronosceptor piece is on the second platform.
Second Level 5 Key: This key is located at the end of the corridor found at the bottom of the large descending stairs that you activate with a switch on the upper platform to the left. The only way to the switch is to go up and around to the right.
Third Level 5 Key: Beat the boss at the end of the level and you'll be rewarded with the third level 5 key.
Third Chronosceptor Piece: Climb the vine wall in the northwest corner of the map as you take the platforms to the boss temple and you'll find the piece you seek.
Second Level 6 Key: After you cross the bridge at the beginning of the level, go to the southeast corner of the open area and you'll see a small ledge. Follow the path and you'll come to the second level 6 key.
First Level 8 Key: This key is just to left as you enter the level, but you can only get to it by falling into the water and heading west to the underwater cavern that leads to a series of jumps. Follow the path and you'll find the key.
Fourth Chronosceptor Piece: At the intersection where you took a right to get the first level 6 key take the left route. This will lead to a large temple, to the left of which is the fireball dude. Kill him and take the teleporter that faces due east (the other six just drop you in the lava). This path will lead to the Chronosceptor piece. Hint: If you're having trouble exiting the area and have an extra life, try avoiding the save point and heading straight for the Chronosceptor piece. After you get it, die, and you'll come back to life at the checkpoint outside the dungeon with your Chronosceptor piece in hand.
Third Level 6 Key: Take the same route you would take to get to the Chronosceptor piece, but don't go into the drain in the hallway. Instead go down the hallway, solve the catacomb switch junction, go through the cavern, then you'll find the key on top of the structure in the center of the pool.
Second Level 8 Key: Head down into the catacombs and then enter either of the two doors in the first room you enter. Kill the fireball demon, then head up the stairs. Follow the path (even through the swinging hooks) until you get to the key room with a fireball demon. Kill the demon and he'll give you access to the key.
Third Level 8 Key: Head down into the catacombs and enter either of the two doors in the first room you enter. Jump into the water behind where the fireball demon is, or was, and head down. At the bottom of the pool is a tunnel that leads to a transporter that will take you to a boss. Beat the Mantis and the key is yours.
Third Level 7 Key: First, you must find the big tree and travel up into the treetops. Once you reach the first checkpoint, the path splits three ways for the first time. Take the path to the east and it will bring you to the third level 7 key.
Second Level 7 Key: Again, you must find the big tree and travel up into the treetops. Once you reach the first checkpoint the path splits three ways for the first time. Take the path to the west and follow it to a save point and a transporter. Take the transporter and go through the villages and then through the gate. Continue on down the path until you enter a cave with a save point. As you exit the cave, you'll see a small patch of grass to the left (or south). Use the platform to get to the southern cave and then follow the path. Now, you'll need to jump off the platform with the rocket to get down to the second level 7 key.
First Level 7 Key: From the point where you jumped off onto the small grass platform to go to the south (and the second level 7 key) cave, head across the footbridge and through the village to the transporter. Follow the path and it will lead you to the first level 7 key.
Sixth Chronosceptor Piece: Take the eastern path from where you got the first level 7 key, and it will lead you to the exit transporter. To the left of the exit transporter there is a small ridge on the side of the cliff. Drop down and then jump over to the platform to claim your prize.
Fourth Level 8 Key: From the moving platforms, you must blast your way through some tight spots and make some difficult jumps. You must kill everyone along this path, otherwise the platforms that you need to make the jumps won't appear. At the end you'll find the fourth level 8 key. Take the transporter to the left and you're on your way.
Fifth Level 8 Key: After the transporter, just keep following the path. Just past the next checkpoint you'll find a switch along the wall on the right side (or south). Activate it, and head back west. Along the north wall, there will be an opening behind a platform (it is shown as a large pink square on your map). Follow the passage and it will lead you to the fifth level 8 key.
Eighth Chronosceptor Piece: This one's easy. It's in the same room as the save point right after you defeat the T-Rex. That is, if you can beat the T-Rex.Fifth Level 8 Key: After the transporter, just keep following the path. Just past the next checkpoint you'll find a switch along the wall on the right side (or south). Activate it, and head back west. Along the north wall, there will be an opening behind a platform (it is shown as a large pink square on your map). Follow the passage and it will lead you to the fifth level 8 key.