Erosion, water damage, freeze-thaw cycles, foundation settlement (these are literally mountains of stone built on sand), vandalism and other intentional damage, floodplain evolution.
That last is particularly noteworthy as the Nile famously floods on an annual basis, and that itself is the basis for Egyptian civilisation as those floods created what is still one of the most fantastically productive breadbaskets of the world. Ancient Rome relied on Egypt for grain, and even today demographics data and more vividly night-time satellite light-pollution imagery reveal the Nile as a highly-populated ribbon within a sea of darkness and desolation.
The pyramids have withstood multiple risks for many thousands of years. Despite their simple and rugged overall architecture, that remains impressive.
8bitsrule|17 days ago
dredmorbius|16 days ago
That last is particularly noteworthy as the Nile famously floods on an annual basis, and that itself is the basis for Egyptian civilisation as those floods created what is still one of the most fantastically productive breadbaskets of the world. Ancient Rome relied on Egypt for grain, and even today demographics data and more vividly night-time satellite light-pollution imagery reveal the Nile as a highly-populated ribbon within a sea of darkness and desolation.
The pyramids have withstood multiple risks for many thousands of years. Despite their simple and rugged overall architecture, that remains impressive.