There are many different collectibles to be found in Kao the Kangaroo, with one of them being Runes. These little stone tablets with purple writing on them will be used to unlock new stages, so they are kind of forced on you to progress through the game. This page will detail the locations of all the Runes found in The Lava Caves.
Rune #1 Location
All of the Runes in The Lava Caves are pretty much impossible to miss, as they are all on the main path and will be right in plain sight. The first Rune will be found fairly early in the level, and is actually the first collectible. When you learn about setting the boomerangs on fire, you will need to use that flaming boomerang to hit a spider’s web that is holding up a crate. Once you do this, use the crate to jump across the lava and the Rune will be right there.
Rune #2 Location
During the stage, you will encounter a bridge that is raised, which will be blocking your progress. You’ll need to take a side path and use a boomerang to hit a furnace on the other side of the area. Once you do this, the bridge will be lowered and the Rune will be on it.
Rune #3 Location
Upon reaching a larger room that is filled with pipes, the bottom portion will have lasers throughout it. On the other side of where you entered is the place you need to go, with you having to bust through some more webbing. On the other side of the webbing will be the Rune.
Rune #4 Location
The final Rune in The Lava Caves will appear in the final room of the level, which is Gadget’s garage. Here, you need to align three lasers on the machine powering the forcefield in the middle of the room. Once you complete this and collect the wrench for Gadget, the fourth Rune will spawn in front of the exit.