Tomb of Amenemhat III (Location)
The door is at the very base of the pyramid's southwest corner.
This tomb is fairly linear. Loot some silica from the initial passage, and then proceed through the broken roof.
The room above has some loot, and several doors, but all dead-end except one, which leads to a large chamber with a sealed door.
Break through the two wooden panels in the floor to reveal a sand-seal behind each one. Break them.
Pass through the no-longer sealed door, loot some silica from the passage, and emerge in a dark colonnade with a pool.
There are a lot of crocs here. A trance-inducing weapon will let you dispatch them easily, and see them in the darkness.
Loot this level, then try the passages out. One is the way you came in, two are blocked, and one leads to stairs up. Loot this level as well, then dive into the pool.
And underwater tunnel leads on, but there are side passages with additional loot.
At the end of the passage (still underwater) is the location tablet.
You can fast travel out, but it's worth surfacing here and looting the chambers. An exit can be found by climbing the Sobek statue, and sliding away a blocking rack.
