Sphinx Passageway (Location)
Found by entering the secret passage at the base of the Great Sphinx.
In the first 'dead end,' one of the cubbyholes is actually a tunnel forward.
You'll come across a cobwebbed shaft down. Leap over it to find a treasure room with two of the location's lootables
Descend the cobwebby hole you just jumped over. These dark rooms will eventually lead you to the Well of Souls secret map chamber.
You can't do much here until you've completed all Stone Circles and have got 46 Silica in your pocket. You can, however, find the final location lootable through a doorway on the west wall. Loot the white chest for completion.
When you have completed all the Stone Circles, this room will greet you differently.
This will take you to the First Civilization ruin of Eesfet Oon-m'Aa Poo.