>>13780882There are 2 independent explanations for various seemingly-inexplicable moulding and machining of impossibly hard stone structures:
1) Of the kind in OP's picture, and of the kind in ancient Egypt (for example), this is a lost and still unknown concrete technology. There are ideas involving geopolymers today, but they aren't sufficient to explain the kind of concrete that these people could make back then.
When this concrete was made, it had to have a clay-like consistency, that only hardened later. The undeniable proof that a clay-like state of granite was achieved by these people is in the many granite statues of ancient Egypt.
All of these statues are actually hollow. Some have rocks inside, that acted as a foundational structure that the sculptor "packed" the granite clay on top of, to form the mold. Here is a video that explores this idea (there are others):
https://www.youtube.com/watch?v=9ZVNbwbyGPYThis kind of concrete, when in clay form, can be cut or drilled with basic clay scultping tools. The tools are not the mystery, its the clay-like concrete that hardens to stone.
2) There are other structures that are actually petrified wood, which have petrified after having been submerged under clay from the bottom of the sea after a global cataclysm in which the waters of the Earth rose by an unimaginable amount in a very short time. The wood in these structures, over unknown millenia, accreted limestone and other hard stone slowly from clay in the sea, and over time the original wood rotted away and deteriorated, leaving the natural stone mold afterwards - giving the appearance that carved wood structures were actually carved stone structures.
