Needless to say, the cold air we felt outside the tomb gate just now was emanating from this cold pool.

The only thing that makes me a little curious is how there can be such a cold pool in this underground.

It stands to reason that Runan County is located in a plain area, and the temperature on both the surface and underground is relatively average, so there should be no cold pools like this.

"Be careful, I think there's something strange about this cold pool." I reminded everyone. Because of the relationship between geothermal energy, the temperature below the surface is relatively average under normal circumstances, except for some places on the plateau that are permafrost all year round, such a cold situation rarely occurs.

In fact, there is no need for me to remind anything, everyone became vigilant at the same time when they saw this cold pool.

"Well, it's a bit weird." Li Huiyan nodded and continued: "No matter how you look at it, there shouldn't be such a place in Runan County, let alone in an ancient tomb, most of the things are strange. "If such a cold pool appeared in the ancient tomb, if it was not naturally formed, then it is very likely that it was thought to have been made.

If the former is fine, although it is unlikely to happen in such a zone, it is not impossible, after all, the magic of nature is far from what ordinary people can imagine.

But if it is the latter, it makes people feel a little incredible, what kind of method did the owner of the tomb use in the first place to build such a cold pool, which is almost impossible to do, at least in ancient times without refrigeration conditions.

As we continued to get closer to Hantan, the temperature in the cave became more and more unbearable, Dong Shuang, who was more afraid of the cold, had stopped and did not dare to move forward, and Xiao Yue finally stayed in place to accompany her.

Approaching the cold pool, I found that there were four half-meter-high circular stone pillars erected around the cold pool, each of which was wrapped with a bronze chain the thickness of an arm, and the other end of the chain was submerged in the cold pool.

There was always a lot of white mist on the surface, so we couldn't see what was beneath the cold pool.

However, since it needs to be locked with four bronze chains as thick as this, and what is hidden in the cold pool is not ordinary, it can't help but make me secretly careful.

"Do you think this cold pool is man-made or natural?" After staring at Hantan for a few moments, I asked Li Huiyan and Qin Gong on the side.

"There's no way to know for sure, it's mostly natural, after all, it's unlikely that a cold pool like this is artificially created." Li Huiyan thought for a while and said.

"Well, you can see that there are traces of artificial excavation around the cold pool, most likely because the owner of the tomb accidentally discovered this cold pool when he was building the mausoleum, and then expanded it slightly." Qin Gong also nodded and said.

"You think the same as me, and you don't think a cold pool like this is artificially built." I said.

From the moment I entered the cave, I carefully observed the situation around the cave, and found that the stone walls around the cave were uneven, and there were almost no traces of artificial construction.

If this cold pool was really man-made, then the cave should also be built in a very beautiful and neat way, but this is not the case at all.

"Have you seen what's inside this pool?" I asked again. Since just now, I have been staring at Hantan with wide eyes, but the more I look at everything in front of me, the more blurred it becomes, and the fog on the surface of Hantan is much thicker than just now.

"I can't see clearly, if only I could blow away all this cold air coming out of the cold pool." Li Huiyan said.

As soon as the words fell, I suddenly heard a sound of water from the cold pool, and then there were ripples on the surface of the cold pool.

The sudden sound made me feel a little uncertain, and I couldn't help but take two steps back. Could it be that there are still living creatures in this cold pool?

I thought to myself. But when we carefully observed the cold pool, the cold pool was calm again, as if the sound of water and ripples had never appeared.

"Let's all be careful, this cold pool is really weird." Li Huiyan reminded.

I nodded, in fact, I don't need to be reminded by Li Huiyan, I already know what to do. There are countless strange things in the ancient tomb, and if we don't face everything carefully, it's hard to say whether we will be able to get out of the tomb alive.

After that, we didn't speak again, just stood quietly on the edge of the cold pool, waiting for the movement to come from the cold pool again.

After waiting for about two or three minutes, there was still no gain, and the entire cave, including the cold pool, was a little quiet, and all that could be heard was the sound of each other's heavy breathing.

"Sister Lizi, it's so cold here, when are we going to leave here?" Xiao Yue shouted not far away.

"Wait a little longer, if you feel cold, go outside the cave first, and we'll call you when we're ready to leave." Li Huimin said.

Xiao Yue sighed, and then pulled Dong Shuang out of the cave, it seemed that he really couldn't stand the cold inside the cave, and was ready to go outside to guard.

"Could it be that we thought too much about it, maybe the movement just now was just a small bubble coming out of the bottom of the cold pool, in fact, there was nothing in the cold pool at all." After standing on the edge of the cold pool for a while, even I felt that I couldn't stand it, so I said.

"The movement just now doesn't seem to be caused by bubbles, it's clearly the sound of something swimming in the cold pool." Li Huiyan shook her head and said.

At the same time, the thousand-year-old turtle that I had just unceremoniously thrown into the kit suddenly became restless, clutching the kit with its paws, as if it wanted to get out of it.

I hesitated slightly, but carefully took it out of my kit and placed it on the ground by the cold pool.

After a while, as if sensing that there was no danger from the outside world, the thousand-year-old turtle stretched out its limbs and head, turned around and quickly crawled towards the cold pool.

The thousand-year-old tortoise was very fast, and almost in the blink of an eye, it ran to the edge of the cold pool, but it did not jump directly into the cold pool.

It can be seen that the turtle seems to be a little afraid of something in the cold pool, and it looks very anxious when standing on the edge of the cold pool, but it just doesn't dare to jump down.

"Why do I think that the hometown of this thousand-year-old turtle seems to be this cold pool, do you feel this way?" I asked Li Huiyan and Qin Gong.

"It's not clear if it's a cold pool, but there's something in the cold pool that scares it, that's for sure." Li Huiyan said.

That is, when the thousand-year-old turtle ran to the edge of the cold pool, a series of water sounds were remembered again in the cold pool, and many ripples rippled again.

Before we could think about it, we suddenly saw a white thing coming out of the cold pool and rushing straight to the thousand-year-old turtle on the edge of the cold pool.

When the thing flew closer, I could see it clearly, and it turned out to be a big snow-white fish.

This big white fish is very vicious, not only are there countless spikes on the surface of its body, but its large open mouth is also covered with rows of sharp teeth, giving people the feeling that even steel plates can be easily bitten through.

What's even more incredible is that this snow-white fish doesn't have eyes, and the place where it should have eyes has become two deep depressions, which looks very strange.

It's not uncommon for some creatures that live underground all year round to have no eyes.

Because the role of the eyes in the dark underground is almost zero, the eyes of many creatures will gradually degenerate, and to evolve things like smell, which is also a necessary choice to adapt to the environment.

The thousand-year-old tortoise apparently noticed the eyeless fish that had jumped up in the cold pool, and its limbs and head retracted into the shell of the turtle as the eyeless fish flew over and was about to bite it.

A crisp sound came, probably because the eyeless fish did not jump up hard enough, and did not fly directly to the place where the thousand-year-old turtle was, but instead bit on the edge of the cold pool.

As if cutting tofu, the eyeless fish bit a gap in the stone on the edge of the cold pool in one bite, leaving a row of extremely neat tooth marks.

"Thank God, fortunately, we didn't venture to approach Hantan, otherwise if we were bitten by this fish, we would probably have to tear off a piece of meat directly." The scene in front of me made me smack my tongue a little, and I said very scared.

"Well, if I'm not mistaken, this should be an eyeless fish." Li Huiyan nodded and said.

"Eyeless fish, what is that, it should be very ferocious, why haven't you seen it anywhere else?" I asked.

"I don't know much about the eyeless fish, except that it was a creature that existed during the Ice Age. However, at that time, its body was dozens or even hundreds of times larger than it is now, and biologists had long concluded that the eyeless fish was extinct, but they did not expect to see it in such a place. Li Huiyan said.

"It was there during the Ice Age, and you said it wouldn't like to live in a cold place, so it would be in this cold pool." I said.

"It's not very clear, the climate on Earth has changed countless times since the Ice Age. I suspect that most of the eyeless fish are also trying to escape natural disasters, so they choose to hide underground, and over time their eyes will deteriorate. Li Huiyan said.

When I saw the eyeless fish, I remembered the ghouling fish I saw in Bai Qi's tomb at the beginning.

Although the appearance of these two fish is different, the ferocity is almost the same, and both live underground.

"But something is not quite right, is there an underground river here, how could this eyeless fish come into this cold pool?" I said.

"Most of them were put in by the owner of the tomb back then, and the world of eyeless fish extinction is not long, and it will still appear occasionally a thousand years ago. Perhaps the owner of the tomb took a fancy to the ferocity of the eyeless fish, so he placed it in the cold pool to guard the ancient tomb. Li Huiyan thought for a while and said.