TL;DR: The striped block in the wall is granite with two vertical recesses—very likely a door/portcullis jamb or latch-seat re-used in the rubble.
Granite “Lock Block” at Saqqara: a Mechanical…
TL;DR: The striped block in the wall is granite with two vertical recesses—very likely a door/portcullis jamb or latch-seat re-used in the rubble.