At the heart of Saqqara is the funerary complex of Djoser, including the step pyramid, built of stone (instead of mud brick) by the architect Imhotep. (Imhotep was an all around genius. As a physician, he was deified centuries after his death by the Greeks, who identified him with their healer-god, Asclepius.)
The complex was surrounded by an immense stone wall, a portion of which, reconstructed, is shown here, baking under a clear blue sky in the hot Egyptian sun as it has for millennia. To enter through the narrow door, click on the photograph.