The Seat of Eternity was discovered by another but couldn't solve the puzzle, and we can help you find the solution.
The Seat of Eternity mystery is one you can stumble upon while exploring Gizeh in Indiana Jones and the Great Circle. You do have to go out of your way to find this location, and once you do, you'll need to continue the work of a previous archeologist.
The one who discovered this location could not figure out the puzzle and suffered for it. Thankfully, they provided a few clues on what you need to piece together the final details of this area. You'll need to search around for every piece of this puzzle, and after you have them all together, it's about placing them in the correct locations. Once you do, you can unlock the tomb and obtain a helpful collection item you might be hunting for. Here's what you need to know about how to complete the Seat of Eternity mystery in Indiana Jones and the Great Circle.
Finding where you can start the Seat of Eternity mystery takes effort. Even if you have the Gizeh mystery pamphlet you can get from Asmaa from the Village Market, discovering this exact location can be a little tricky. You'll know where to go, but you have to jump into the massive pit that can easily hit you for a lot of damage if you just jump straight in.
The best way to navigate down into this pit is to aim for the first hole and go for the small ledges around the side. You should be able to drop down on this side without taking any damage. You can safely drop into the rest of the pit and proceed to the mystery. Thankfully, there are no dangers or enemies in this area that you have to worry about, such as the guards protecting the Cloud Atlas lockbox mystery.
When you get into the proper area with the tomb, there's a dead body on the ground with a note next to it. You can grab the note and read how the person purchased a similar pamphlet to learn about this location from the Village Market back in 1882. Although they were unable to figure out how to open the sarcophagus, they do hint that it has something to do with the various canopic jars you need to find, which they have next to their body.
There are four canopic jars you need to track down hidden within the tomb, and you need to place them at the proper locations. The first one should be next to the body with the note, but the next two are trickier.
From the dead body, proceed down the path you initially dropped down from in the pit, and then take a left. There's a large gap between you and the other side, and you can toss your whip on a platform above you. Attach the whip to this point and lower yourself down. You'll find the second canopic jar and a large melee item. Grab them both, and throw them on the side you came from. It would help if you had them both for later.
Before you return the way you came from the pit, attach your whip to the pole hanging above your head again and swing to the other side. On the left is a closed-off gate, but you can use your whip to yank it open, and the third canopic jar is on the other side. Take it to toss onto the side where you threw the previous jar and the melee weapon. You can safely return to the original area, but you're still missing the final canopic jar to complete this Indiana Jones mystery.
You'll find it directly across from your position from where you were crossing the gap. Pick up the two-handed melee weapon and use it to bash in the flimsy stone wall opposite of you. The fourth jar will be here, and you can bring them back to the antechamber, and now it's time to place them in the correct locations.
The proper locations for each canopic jar are reflected on the murals behind the pedestals. The final two are a little tricky, as the murals are partially covered and destroyed. If you start from where you entered the antechamber, from left to right, it should be the Human jar, the Falcon jar, the Jackal jar, and then the Baboon jar.
After they're all in their proper places, the sarcophagus should open up, and you can find the treasure within it: an Ancient Artifact. You'll need to collect 14 more of these artifacts to complete the set for Gizeh in Indiana Jones, similar to the ancient artifacts you discovered while exploring the Vatican.