The cave hall presented in front of us has a square on the ground, with a side length of about 15 meters and a height of about 13 meters! The cave wall is composed of four triangular inclined planes, and the four inclined planes converge at the top from all sides to form a point, which is clearly a hollow pyramid!!

The sudden scene in front of him made the three of them involuntarily scream at the same time, and Hong Kaiyuan also scolded: ", have we won the jackpot in the two-color ball?"

I didn't make a sound, thinking of everything before, a chill appeared in my heart again, and I said, it seems that this time my ass is difficult to wipe clean!

Soon, however, surprise was followed by disappointment, because it was empty, nothing!

All three of them were a little unrelenting, and searched around the pyramid again, but found nothing. Pen @ fun @ pavilion wWw. ｂｉｑUｇE。 info And, apart from the passage we came into, there are no other passages here.

At this time, Wen Jing began to be a little irritable: "What is this for, why do you have to make it look like a pyramid? Why is there nothing?"

"God knows!" Hong Kaiyuan sighed, "The more I look at this place, the more strange it becomes! Under normal circumstances, it is necessary to make a hole in the shape of a pyramid, and it is so regular?"

After a pause, he also turned on the flashlight and shone everywhere: "Lao Tzu doesn't believe in evil, and I can't find clues anywhere!"

I stood in the middle of the cave hall and didn't move, looking at this strange pyramid, my heart suddenly moved, and I said to Hong Kaiyuan: "Fatty, don't you think that this place is the same as the two outside, except that it is a little smaller?"

Hearing this, Hong Kaiyuan patted his head and immediately shouted: "Why didn't I think of this? This is definitely the same! ******, Lao Tzu only thought of this now!"

Wen Jingzheng also looked around, and when she heard us say this, she also turned her head: "Oh?

"You see, the two cave halls we are in front of us are too huge, and the penetration of our flashlight is poor, and the dome of the cave is too high, so we can't see anything on the top or top in the dark, so we can't judge it for a while!" Hong Kaiyuan obviously had already figured it out, so he continued: "The ground of the two caves in front is also square, and the four sides are also inclined to the middle and upward, and they must also meet at the top, in fact, it is also a hollow pyramid!" The only difference is that the bottom of the two caves in front of them is rectangular, while the bottom of this one is square!"

Indeed, in the first two cave halls, we didn't think of this at all because we couldn't see the situation on the top of the cave, but now when we see this small cave hall, our hearts are suddenly much clearer.

Over there, Hong Kaiyuan was still scolding and scolding while using his hand to shine everywhere, saying that the flashlight shone on the roof of the cave: "If it weren't for the fact that the roofs of those two caves were too high to be seen, we should have done it a long time ago." He was only halfway through his sentence when he suddenly stopped, and at the same time said "Huh?"

"Old Qi, look, there is a hole in the top of this cave!" Hong Kaiyuan shouted at me, but his gaze did not retract, he was staring at the top of the cave!

Hearing this, I also looked at the place where he was shining, and sure enough, there were many holes at the tip of the cone at the top, about the size of a fist, and judging from the environment here, those holes should be used for ventilation, otherwise we would have suffocated here!

Wen Jing also surrounded her, and the three of them looked at it for a long time, but they didn't see why.

Along the way, the three of them spent a lot of physical strength, so I simply sat on the ground, took out a cigarette, and lit it by myself.

Wen Jing and Hong Kaiyuan were probably tired, so they all sat down. Hong Kaiyuan also snatched the cigarette from my hand and lit one, and the two of them began to swallow clouds and spit fog there, frowning at Wen Jing.

"Can you two smoke less?" she was visibly dissatisfied, "With such a small space, you want to smoke me to death?!"

"Did it smoke you?" Hong Kaiyuan didn't care at all, "This thing is a refreshing thing!"

"Huh, you really can't smoke me!?" Wen Jing said suddenly.

Her 'huh' immediately caught my attention, and indeed, the smoke we had caused didn't spread in all directions, but went straight to the top of the cave. It immediately dawned on me that I was right in my judgment that the holes were supposed to be for ventilation. But for these three connected halls, this one vent alone should not be enough, could it be that the tops of the other two halls are also like this?

Hong Kaiyuan and I had the same idea, but he put forward another opinion: "Hey, Lao Qi, what principle do you say these vents use? It stands to reason that these three stone caves are connected by one word, unless the air flow and air pressure difference are quite large to produce the flow of air, otherwise it is difficult to rely on natural power alone!"

Actually, I'm thinking about this too, even if the vents on the roof of these caves are connected to another cave, and that cave has air flow, in principle, the air pressure in these caves should not be much different, and the natural pressure difference alone is definitely not enough to keep the air in these caves flowing.

This means that it is likely that the things that excavated this cave back then did not require much oxygen, but this is no longer in the scope of my concern.

About five minutes later, when I finished my cigarette, I stood up, patted my buttocks, and slung my bag over my shoulder: "There's no way here, let's go back!"

Wen Hong and the others were a little absent-minded, and they all stood up with blank faces.

And I already had an idea in my heart, and said to the two: "Just in case, I need to set the location here, so I need to use the compass of the mobile phone, or the girl to use the flashlight, and turn off the rest, I look at the GPS, fat man, you are responsible for recording!"

"Do you have a bit of common sense?" Hong Kaiyuan immediately jumped up, "There is not even a cell phone signal here, so that thing will be useful?" And even if there is a signal, we move so slowly, sometimes we barely move, even if it reacts, it can't give you accurate results!"

As soon as I heard it, it dawned on me this time, and at the same time I took out my mobile phone to verify it, and sure enough, the GPS of the mobile phone had no effect at all. I couldn't help but scream: ashamed!

"I've thought it through, I've brought a real compass!"

Looking at Hong Kaiyuan's smug appearance, I suddenly felt a trace of uneasiness in my heart, but this feeling was fleeting and I couldn't grasp it, I always felt a little weird, but I couldn't tell where the fault was!

But soon, Hong Kaiyuan wilted, it turned out that he took out the compass and tried it, and found that it didn't work at all, no matter how he fiddled, it seemed to keep calling, and Hong Kaiyuan, who was in a hurry, scratched his ears and cheeks there.

My heart was ticking, could it be a hollow pyramid that had disturbed the magnetic field here, but I said, "You're a kid's thing, aren't you?"

"It should be broken!" Hong Kaiyuan scratched his scalp.

"Could it be the reason for the structure of the cave hall here?!" Wen Jing and I thought of one thing on the side, "I remember that there are many unexplained phenomena in the legendary pyramid! Why don't you try the compass on your mobile phone again?"

"But I've never heard that the magnetic field in the pyramid will be chaotic?" Hong Kaiyuan is not a lonely person. "If it's really caused by a magnetic field, the compass on the phone is also useless!"

Wen Jing ignored him, took out her phone and began to fiddle with it, and soon, she sighed, looked at the two of us and shook her head.

"I said sister, although I haven't seen the world, but after all, it's your imperial brother, at least how old is it?" Hong Kaiyuan shook his head and began to make trouble again!

Wen Jing cut and didn't answer again.

"Then now I can only use the stupidest way, trace all the way back, and then orient myself when I get to the exit!" I had to say. "Fatty, your hand-drawing ability is better than mine, and this matter will be left to you. Hong Kaiyuan gave me a blank look, saying that he was speechless to me, but he did not object, and found paper and pen from his bag.

On the way back, the three of them were a little depressed, and they didn't say a word.

Back in the main tunnel, the flashlight I had placed there was still there, and there was nothing unusual except that the light had dimmed a lot. As an abundance of caution, I also erased the words I had engraved earlier. Not long after, we walked back to the original resting position, Hong Kaiyuan's bag is still there, it seems that no one else here has come in except for the three of us, seeing this, I feel a lot more steady.

Hong Kaiyuan stopped drawing, handed me the paper in his hand, returned Wen Jing's backpack to her, and picked up the backpack on the ground.

At this time, Wen Jing, who was putting a strap on her shoulder, suddenly stopped and asked the original question: "Hey, you two say, what is the builder of this pyramid for, what is it used to build such a huge project hundreds of meters underground?"