Serapeum Temple is the biggest mystery of the ancient Egyptians

The Temple of the Serapeum is a group of tunnels, vaults, and caves dug under the rocks of the Saqqara plateau with a length of 400 m. How did the ancient Egyptians and how did they use technology and machines to dig such tunnels 5000 thousand years ago, which can only be implemented with drilling machines such as the Suez Canal tunnels.
The strange thing about the Serapeum is also that it contains 26 huge, well-made granite sarcophagi, the lid of the coffin weighs 30 tons, and the body of the coffin itself is 70 tons, which means that it needs nearly 500 men to move each box!!
The strange thing is that the tunnels do not accommodate this number of workers to move these coffins inside!!

The strange thing is that these huge coffins are all made of high-hardness rocks (red granite - black granite - basalt - schist - quartz), which are rocks that can only be dealt with by diamond cutters and a technology that is only found in factories of modern warships, and it does not make sense for anyone to By carving them with primitive tools that were used in the era of the dynasties, which are respectively (stones - copper - bronze - then iron in the later ages), all of them cannot be dealt with at all with these tools, let alone polishing and smoothing them and under them with drawings in this way!

But the question here is why these coffins were made and for whom and why were all coffins empty and closed when they were discovered, except for one coffin. When the archaeological mission tried to move the lid of the coffin with dozens of workers, it could not. Then the mission used dynamite to open the coffin and they found nothing inside the coffins!!
Why was no mummy or a carcass of the body of the Apis calf found in any of them, as Auguste Marit Pasha, the discoverer of the tomb claimed?
Who made it, how and why it was made, why it is so huge, and in the end, how did they move it into the corridors and narrow tunnels of the Serapeum?

The catacombs of the Serapeum are in themselves a dilemma. In the summer you find them cold and in the winter it is hot. The tunnels are 400 meters long. They are dug in the heart of the rock of the Saqqara plateau, not in the middle of the sand, and the tunnel descends to it by a stepped ladder. If you look at the map of the tunnels below, you will find many branches.
In the main tunnel, at those spaces visible on the map, there are boxes, and there are other branches as well. If we look at the main corridor, we find it on the same straight line. Is it possible that this long tunnel was only dug by pickaxes?
The tunnels of the Serapeum have only one door, which is the entrance and exit. The vision is inside the tunnels, even with the sun being very dim, so did they dug all that distance that deep in the darkness and brought out a pile of tons on the lights of the fire torches
It is strange that there is no trace of the positions of the torches on the walls of the tunnel, just as any fire torches at that depth with the backfill and the dirt would be hard and suffocating work.

Given the roundness and straightness of the tunnel, is it possible for a human hand to dig a tunnel with such accuracy and integrity for this distance? Rather, it can be said that this is impossible without a drilling machine, because the tunnels are not dug in the sand, but are dug in the rocks of Saqqara, which certainly requires an incredible double effort to be done through The human hand alone, but it is powerful and advanced machines that accomplished this work, as if we look at our contemporary civilization, we will find that to dig a tunnel-like this, we will need a tunneling machine.
Then we come to the coffins of the Serapeum itself, which is a scientific and engineering miracle. Even in our time, these coffins were not built but were carved like any sarcophagus. It consists of 4 sides, a base, and a lid.
The body of the coffin itself was carved by cutting a solid block of granite of various types from quarries located in the south of the country, such as Luxor, Aswan, Sudan, Sinai, the Red Sea, and Fayoum. After cutting that block, estimated at approximately 80 tons, from the quarry, it is dug and polished, and then the cover is carved.
There is no doubt that shovels and primitive road machines cannot produce such a unique geometric product. All the inner and outer corners of the box are a perfect 90 degrees, neither 90.1 nor 89.9 also the flatness coefficient with an error rate of less than 0.02%, a degree that cannot be reached in the modern era except by using machines High-resolution or optical-optical technology such as laser to obtain perfect flatness.
Then we come to the most important question:
How were those giant coffins placed inside the tunnel that has one very narrow entrance?
It is worth mentioning that King Farouk tried to get one of the coffins out of the tunnel and used many workers and mules, and he was unable to move it from its place except for a few meters, and it was left in its place until now!!