Colossal Guardians

Objectives
Obtain the Stone of the Moon and the Stone of the Sun from the Colossal Guardians.
 * Stone of the Moon
 * Stone of the Sun

Description
The chest containing the scepter appears to be magically sealed and will not budge.

The plaque above it depicts two giant statues holding star and moon-shaped stone sockets at their center.

The two statues are pictured guarding pyramids that look like the ones outside.

Perhaps it's worth your while to investigate these.

Rewards
You will receive:

Progress
You wipe away the sand from the hieroglyphs only for them to become covered in a new layer. You'd best hurry.

Completion
You place the two gems inside the sockets in the wall.