A. Kungurov's commentary: Photography by Prokudin-Gorsky and contemporary photography.
It is clearly seen that over the past 100 years there has been severe destruction.
It can be assumed that the structure is not hundreds of thousands of years old, but much younger and closer to us on the time scale.
And a significant increase in the number and size of trees over these hundred years.
Here are other examples of increasing the number and size of trees:
Promotional video:
Another observation: the rivers become shallow and overgrown. Although, with an increase in the number of trees along the channel, this should not happen. Trees contain moisture and prevent rivers from shallowing.
It happens, and the opposite picture:
According to this logic, most of the kremlin are reconstructions.
Who or what destroyed the fortresses? And where did the ancient builders get so many river boulders of this size?