PS: Thank you for the monthly pass of Jing Shiyan and Wanton Boots.

The entrance to the secret passage is in a pile of rubble under a hill deep in the grassland.

"How can there be a hole here?" Butterfly asked curiously, "Who hit it?" ”

Before Sang Zhuo could answer, Zhou Chu already understood the shape and appearance of the stones around the entrance, so he took it as he walked down.

"Karst landform, karstlandform, is a general term for the surface and underground forms formed by water with dissolving power after dissolving soluble rocks, also known as karst landforms. The term karst Karst derives from the name of the carbonate plateau of the Istrian peninsula in the northwestern part of the former Yugoslavia, locally known as Kras, which means a place where the rocks are exposed, covering a total area of 10% of the total area of the earth. From the tropics to the cold zone, from the mainland to the islands, there are karst landforms. Among the karst landforms in China, the eastern part of the Yunnan-Guizhou Plateau occupies the largest area in West China, Yunnan-Guizhou, Sichuan-Qinghai and Qinghai, and is one of the largest karst areas in the world. It is also found in Tibet and some areas in the north. ”

"The biggest feature of this landform is the karst caves and various underground caves that are strange and naturally formed, such as the one in front of me is a typical example." Gao Ming took over, "Obviously, this is at the junction of karst landform and grassland landform, and the valley of the Imperial Tomb is this typical landform, I'm just a little strange, when did you also know something about geology?" ”

"I understand a little." Zhou Chu replied to Gao Ming's words, "Don't forget the description just now. There is a saying that there are karst regions in China, including West China Province, and I grew up in a small mountain town with this landform, so how could I not know and not understand this. ”

"That's a lot." Gao Ming said, but quickly returned to the topic, "Sandruk, there won't be a naturally formed cave here that leads directly to the angel's tomb, right?" ”

"There's no such thing as a coincidence." Sandra led the way in front and could hear her voice coming from the front, "Just a more coincidental coincidence." ”

Under Sang Zhuo's description, Zhou Chu and Gao Ming and others understood how this secret passage came about, and what kind of coincidence it was.

The cave where they are walking right now. It was not directly to the Imperial Tomb. Eventually, this cave only led them to a larger underground cavern, where an underground river passed it, and when Noorliste was built. Because of the proximity to the valley. So then Noorlist. An underground sewerage and drainage system was introduced, many of which were transferred underground to the cliffs on the side of the valley. Or enter the underground river on this side of the karst landscape.

And the imperial mausoleum, I don't know which grand duke or emperor entered the brain, or the palace conspiracy and political struggle at that time, when the tomb of a certain grand duke or king was built, someone built an escape passage from the inside of the imperial mausoleum, through all the tombs, and a certain exit of this secret passage is located in this underground river.

As a result, the caves naturally formed by the karst landform, the underground drainage system of Noorlist, and the escape passage of the Imperial Tomb were all concentrated on a certain section of the path of this underground river, and no one has ever discovered and noticed this.

And it was also a coincidence that Sandro's people discovered this, when one of her clansmen, who accidentally killed a person in Noorlistri, broke into the underground drainage system in the process of escaping from pursuit, and came to the underground river by mistake, and then strayed into the entrance of the secret passage to the imperial tomb while looking for a way out, so all this was learned by Sandro's people.

"It's really ......," Gao Ming sighed, "but then again, the underground drainage system, this one really surprised me, it was much more advanced than our medieval period. ”

"After all, with alchemy and magic, it is possible to develop in other ways to some extent, and it is not surprising that the same things and building systems appear in advance." Zhou Chu replied.

During the conversation, the group had come to the underground river, the space of this underground river was indeed larger than the entrance of the cave when entering, and in the faint darkness, a river that was not too rapid could be seen, winding down in the dark space.

"It feels like a tomb robbery note." Gao Ming said, and then looked at Zhou Chu's somewhat surprised gaze, "I've been a little bored lately, so I found this book to read." ”

"You're a little behind." Yan Bo, who was following the team, said, "I've seen it a long time ago, well, it's really well written." ”

Sang Zhuo, who was leading the way in front, listened to the conversation of the group, and was slightly surprised in her heart, although she didn't know what Lu Dao was talking about, but from the perspective of the atmosphere, it was a relaxed and pleasant atmosphere, which was what she was surprised and couldn't understand - didn't they know what Lu Dao was going to face next? No, they know it.

But even if you know the Tao, you can still maintain such a relaxed atmosphere and calm emotions? Are the visitors from the otherworldly realm so psychologically strong, or so confident? Sang Zhuo let out a long breath, at least this strength and confidence was a good thing, at least she would never want her clan to be attached to someone who didn't even have confidence in herself.

The group walked some more distance in the darkness, and when they came to a bend in the river, Sandra stopped, whistled, and a torch was lit behind him.

"It's up there, near the third hole on the left."

By the light of the torches, everyone could see that on the wall of the cave on their side, there were some large and small holes that had been constructed by erosion and geological changes, and the cave that Sandra was talking about was not very high, about three or four meters high, and it was also large enough that it was easy to distinguish it from other caves.

"Then we'll go up." Gao Ming said, commanding the two magicians and Wang Shi who came with him to step forward, first Wang Shi, he nailed some iron nails that seemed to be used for climbing into the rock wall, and then the two magicians blessed those iron nails with some magic, and then Wang Shi continued to climb upwards, and then nailed new iron nails into them, and tied the rope up.

After repeating this, Gao Ming saw that Zhou Chu was observing and watching, so he explained: "The iron nail is blessed with solidity and mimicry magic, so that the actual volume of the iron nail is larger when stepped on, and it is also more conducive to landing, and the rope is also strong and mimicky, so that a simple escalator can be immediately created for us to climb up." ”

Just as Gao Ming said, Zhou Chu did feel the fluctuations of magic from those iron nails and ropes with rings, and was able to know through those magic fluctuations that some magic fluctuations were forming qualitative energy outside the iron nails and ropes.

In just a few minutes, a soft ladder made of the simplest tools and magic had already formed there, and Wang Shi also climbed into the hole, and a moment later, he poked his head out.

"Safety." (To be continued......)