Why the Persians made these holes in the desert

Why the Persians made these STRANGE holes in the desert

Undoubtedly, the Persian civilization knew how to take advantage of the intellects of the time, thus managing to create great inventions and build impressive cities, such as Susa or Persepolis.

But, much of its success was due to the efficient way of managing water. Especially when they faced desert and arid climates.
One of his great inventions was the 'Qanat', consisting of an underground infrastructure that collected and channeled rainwater. This water was flowing through the aquifers and valleys to reach the cities.
The Qanats

This technique of collecting water was developed in Persia in the millennium I a.C. Until extending to other arid countries, like Morocco, Libya, Algeria and others.
The technique consisted in digging a "mother" well on a hill, this well would run its way to find an underground aquifer. Then a tune was built, practically horizontal, from the base of the hill to the water

Of course, the tunnel must have an inclination to be able to transport the water.

In addition to the "mother" well, other vertical wells had to be built. This ensured the ventilation of the water, control, rationing and way of evacuation of the earth when the tunnel was emptied.

Given that it was water filtered by the earth, it was drinkable and clean, so it can be consumed.

At the end of the Qanat a building was built to manage the water and was the place where the inhabitants could obtain the water. Even, make your own private pipes.

This was because the Persian government was obliged to develop these systems to provide water to the city. It was left for each person to make an extension to their lands.
The incredible thing about this system is that it still works. That is why we must be surprised at how they built such wonders at that time.
What do you think of this system?