Han Chen muttered to himself as he headed for the underground direction.

However, he suddenly realized that he seemed to be right.

"Ecological structure, yes, ecological circle!"

Han Chen suddenly woke up.

Whether it is the earth or Zulongxing, there is a complete ecosystem. Under the large ecosystem, there are some small and large ecosystems.

It's just that if those small ecosystems want to maintain their own vitality, they must regularly exchange materials with the large ecosystem, so as to achieve the effect of flowing water without decay.

Moreover, those defensive facilities were successfully constructed in the old age before the advent of God's Domain. That is to say, the enemies defended by those defensive facilities should belong to a civilization.

Therefore, if there are real enemies in the underground world, then the underground world should also have a complete ecosystem.

If this condition is not met, it will not be able to survive in the old age.

Of course, this ecosystem does not necessarily follow human standards, but anyway, such an ecosystem should exist.

"Maybe it was originally an ecological circle, but it was a little different from the earth's ecological circle, and it was not even an ecological circle that chose meat life at all."

"You can’t think according to the consistent thinking of human beings. You must escape such thoughts. There are many races in God’s Domain, such as the Balrog clan, the Rock Clan, the Elf clan, and so on. The ecosystem is also strange, even flesh and blood and plant life What it occupies is just a place among creatures."

"So, it cannot be judged by common sense."

"Of course there is a bigger question in this, and that is why the surface world, even at the expense of some'sentinels', has to conceal news of the underground world."

"The emperor of the Eternal God Dynasty has absolute authority. Those common people don't dare to resist the nobles, and the nobles also don't dare to resist the royal family. Even if such news is accidentally spread, what impact will it have on them? Not so much!"

"For them, civilians only need to accept orders and obey the rule. Can they resist?"

"I always feel as if I have overlooked something."

"what is it?"

With such doubts, Han Chen continued to go deep underground.

"Five meters, six meters, 7 meters 2, 9 meters..."

The deeper, the more spacious the passage.

When the width of the passage reached 12 meters, Han Chen slowed down.

After a period of rest, Han Chen sent the avatar this time to continue marching towards the ground, just as he tried with the avatar just now.

If the upper passage is used to transport troops, then the place that the lower passage leads to is the core of this special ecosystem in all likelihood.

The Eternal God Dynasty has abandoned those abandoned military installations, and the enemies that represent the underground world should have no threats, but this is not absolute.

Han Chen will not pin his hopes on the intelligence of the Eternal Gods.

Even if they think so, it does not mean that their intelligence is correct.

With this thought, Han Chen finally came to a "city".

This is a huge square with a diameter of more than a hundred miles. It seems to be the same as the square on which troops are assembled to attack the surface world, but the biggest difference from the square above is not its area, but the existence of various kinds of squares. All kinds of strange facilities.

The height of the square is more than 30 miles high. Hundreds of huge pillars are supported here. There are also some "stairs" on the pillars, and people who want to go from the top down can go to the square.

There are no houses or common urban buildings on Earth, but some buildings that Han Chen can't directly describe.

The appearance of these buildings is all sorts of strange, if it weren't for the fact that many buildings are completely repetitive, Han Chen would have thought it was natural!

These strange buildings, if they are only superficially viewed, should not be able to see their functions.

From a human perspective, it seems that these things have been abandoned.

"No, it cannot be restricted by human perspective and thinking mode. The things in the underground world are not necessarily human, no, not even human at all."

"So, they may not need houses or city walls. If they have not developed their own civilization and are just a model of social creatures, they don't even need clothes and weapons."

"The repetition rate of these buildings is very high, indicating that they should be constructed manually."

"So, for them, the most important use of these facilities should be to solve the food problem. After all, no matter what kind of life it is, they cannot leave energy extraction. These facilities should be some kind of means to solve the food problem. Other usage."

"I can't see any traces of life activity here. Could it be that the traces here have been deliberately erased? But, even if the traces are deliberately eliminated, the traces themselves should leave traces, right!"

"If the traces of those details have been completely eliminated, why should we leave such a passage and such a ‘city’?"

"Have I made the mistake of thinking about problems from a human perspective again?"

"No, there are only so many human perspectives, even from the perspective of legendary existence, it's just that, why should we consider things that can't be done?"

This is like trying to remove fingerprints from the crime scene. If you want to wash with water, it will leave water stains on the scene. If you wear gloves at the beginning, it will be seen that a person wearing gloves committed the crime. .

Wearing the gloves itself is a clue.

So even if it is to eliminate the traces, and the method of removing the traces is perfect, it can only make people unable to find the clues of the people who have found this plan.

However, it is almost impossible to completely eliminate the evidence.

But the traces on the scene are very perfect, perfect to the point that even some of the details do not exist. The level of perfection is simply creepy.

After all, the creation of these things should also leave some leftovers.

However, just under this perfect elimination of traces, there are traces of passages and cities, which left indelible stains in the process of this perfect elimination of traces.

Even if the environment here is directly destroyed, it is better than keeping the scene!

"There must be some possibility that I didn't think of."

Han Chen searched and recorded all the traces here, while thinking hard, finding a possibility for all kinds of phenomena.

"Could it be that this place was originally like this?"