The ancients had the concept of going into the earth for safety, so in most cases, as long as it is allowed, it will be buried in the soil after death, and at the same time, tombs will be built to place corpses. At that time, both the high-ranking officials and nobles and the ordinary common people paid attention to the need to enter the earth for safety, although they were also buried in the tomb after death, the cost and the tomb built were very different. Rich people and even royal relatives and noble relatives will ask a famous feng shui master to find him a feng shui treasure land when he is alive, and after he finds it, he will start to spend a lot of money to build it, so that the world he goes to after death can be enjoyed as much as he is alive. Therefore, most of the tombs built by rich people and officials and royal relatives are magnificent, with countless gold and silver jewels placed in them, and at the same time, they must be buried together after death, so that in the world after death, these martyrs can continue to serve themselves, and they also know that their tombs contain so many gold and silver jewelry and valuables will definitely be remembered, so in order to prevent theft, they have taken measures when building the tomb. With the change of time and environment, many ancient tombs have been changed by the environment, and they can no longer find their original location. I'll talk about a few things:

The situation of the ancients building tombs
In ancient times, the burial of ordinary people after death is very easy to solve, because there is not so much attention, ordinary people generally find a place to dig a pit, and then buy a thin skin coffin, people in the coffin, directly to the dug pit, and then put the coffin in, in the backfill soil, and finally set up a tombstone to complete. If you are poorer, then you can directly find a thin mat to carry a package of people to the tomb and erect a wooden tombstone, then it is also completed. And ordinary people will not have any valuable funerary goods when they are buried, and they will not be afraid that someone will come to their cemetery. With the passage of time, most ordinary people's tombs will disappear.
As for the rich and powerful and nobles, as well as the relatives of the emperor and the state, the tombs they built after their deaths were much more complicated. Because the ancients believed that what the dead brought to the tomb could be enjoyed in that world, they would place a large number of valuable utensils, gold and silver jewelry and other items in their tombs, hoping that they would continue to live a luxurious life in that world.
So many objects are placed in the tomb, for the owner of the tomb is afraid of theft, after all, this kind of thing abounds in history. It is one thing to have property stolen, and it would be very sad if one's own bones were to be stolen and ruined by thieves. Therefore, choosing a suitable place to build a tomb and doing a good job of anti-theft in the tomb is an extremely important thing.
At that time, to build a tomb for the dignitaries, first of all, we must choose a good feng shui treasure land, and then in this place first dig a large pit, build a good inner tomb, and then build an outer chamber outside the inner tomb, capping, backfilling the soil, building a mound, the approximate process is like this, but involving specific details, it takes a lot of time and energy.
The transformation of the tombs of the ancients
Because of the ancient concept of going into the ground after death, in ancient times, basically people would build tombs for burial after death in order to be safe in the ground. But the environment and times will change, the cemetery will also change, after the death of a person for a maximum of a few years will become white bones, and eventually submerged in the earth, if there is a coffin can be maintained for decades, sarcophagus or coffin made of precious wood can exist for hundreds of years, but the dead inside have long been left with only white bones.
The graves of the rich or the dignitaries will be remembered by thieves, because there are a large number of treasures in them, which has a huge attraction for people without money, so in history, many emperors, princes and officials have been stolen many times by tomb robbers, and there is nothing left. The very few cemeteries that have not been stolen and excavated are due to their special status environment and social environment. Therefore, most of the tombs of the ancients are buried deep in the earth with the change of time and environment.
In summary, as long as the ancient cemeteries were built by rich people or dignitaries, most of the time they could not escape the fate of theft, while the tombs of ordinary people were buried deep in the earth with the changes of the times, and were occasionally discovered.