Tomb of Sneferu (DLC Location)
A pyramid tomb in Saqqara Nome . You'll pass through here in the DLC Mission Secrets of the Pyramids The entrance is just a little ways up the north side, in an obvious opening.
Squeeze through a narrow passage, then reach a room with a scarab wall, and a reminder about secret passages.
Before passing through the crack, look up to see a doorway above.
Pop up there for a note and a chunk of silica, then go back down and through the scarab wall. This passage will lead you across some water and down a shaft, neither of which hold any secrets. Eventually it opens up into a platform puzzle room.
Pick up a spool and walk onto the platform.
Once it's down, slide the mobile rack onto the platform as well.
This is enough to hold the other platform in place while you jump up to the high door beyond.
Up top, smash the pots to clear the passage and find…. two more platform puzzles. The good news is you don't need to solve either of them. In the first room, the left platform has a large pot, and right platform has a number of spindles. If you leap up on the left platform and up the pot, you can just scrabble your way up the wall before the platform falls. There's a treasure chest up top.
In the other room, you can climb up the Thoth statues embedded in the wall.
From there you can jump to the platform, then climb up before it falls.
This brings you to the tablet room of the pyramid. Do note the copious amounts of treasure.
A more modest chest has the quest artifact for Secrets of the First Pyramids.
Loot the room, then read the tablet to complete the location.
Exit through the letter slot, for a passage that will eventually brings you back outside.