After descending to a hundred meters, the trend of the Tiankeng cave was no longer downward, but began to rise and fall, and the air in the cave began to become relatively turbid, but this was no problem for Xiao Yong at all.

Some creatures living underground were just about to react to Xiao Yong's uninvited guest, but Xiao Yong quickly passed through the territory where they were.

Further down, there were basically no creatures, and the air inside the cave became even worse.

Xiao Yong began to hold his breath and move forward, even if he didn't have a cultivation in his body, his perverted physique could allow him to hold his breath for at least thirty minutes without any discomfort.

Even if he felt a little unwell in his body, he could quickly enter the Heavenly Opportunity Land to ventilate and eliminate the negative state of his body.

"It's crystal. ”

More than 300 meters deep into the sinkhole, the temperature in the cave has increased a lot, and it is very humid. The minerals on the cave wall have changed from some unknown metal ores of unknown type when they were more than 100 meters old to a large area of crystal ore of various colors.

"At this depth, there is still mud!"

In the hot and humid sinkhole, Xiao Yong checked these various colored crystals attached to the soil in the four sides of the cave wall for a while, did not destroy them, and continued to move forward.

Through a crystal area nearly 100 meters long that has sunken in the sinkhole, the temperature in the cave has decreased a little, and the strange sound that can be faintly heard at the entrance of the cave can be heard very clearly here.

"There is an underground river. ”

Reaching this depth, Xiao Yongdi's divine thoughts were finally able to probe the bottom of this legendary bottomless sinkhole, which was an underground river with a large flow of water and a huge karst cave with countless stalactites.

As for the strange sound heard, it was formed by the sound of the water flowing in the underground river after it was transmitted over a long distance through the sinkhole.

"It's such a big place, but it can be decorated. ”

Shen Nian observed the huge underground cave, and Xiao Yong's eyes lit up.

The lies buried by Kotoujin have always been a stone in his heart, but fortunately, Zhang Qinghua and his entourage did not find out the details of this sinkhole, which gave Xiao Yong a lot of room to play.

With a distance of more than 600 meters from the cave, even if there were only small holes in a few places that could be passed, Xiao Yong only took more than ten minutes to reach the entrance on the side wall of the top of the cave.

The turbulent underground river formed a rumbling echo in the entire karst cave, Xiao Yong observed the terrain below the cave entrance with his divine thoughts, and found that if he wanted to go down from the cave mouth to the underground river more than 30 meters above the ground, he basically couldn't find a good borrowing point.

But this is not difficult for Xiao Yong, even if he does not bring a rope, in the land of heavenly opportunities, those rattan plants dug in when the Xiao tribe was digging in the wasteland, the newly generated rattan, can be folded a few to be used as ropes.

Entering the Land of Heavenly Machines, Xiao Yong selected a rattan plant that he named Iron Vine, and picked a few rattan sticks that were dozens of meters long.

This kind of rattan grows relatively slender, but the length is very long, and the toughness is excellent, in the land of the Xiao tribe in the flood world, at that time, this iron rattan was one of the most powerful among all the rattan shrubs with the ability to hunt, and it was already on the verge of turning into a spirit.

Using the Houtian Lingbao Bagua Furnace and refining it with a faint separation from the fire, Xiao Yong weaved a few iron rattan rattans, and finally obtained a rope with a length of nearly forty meters.

Thinking that the arrangement of the Tiankeng Karst Cave was a larger project, refining and weaving the iron rattan rope, Xiao Yong did not immediately go out of the place of Tianji, and refined four small stone tablets of Tianji, except for one of the Tiankeng Karst Cave, the other three were reserved for later use.

Taking the iron rattan rope out of the heavenly place, Xiao Yong fixed the iron rattan rope at the entrance of the cave and quickly went down to the bank of the underground river in the cave.

The entire cave was dark, and if it weren't for the divine thoughts, even with Xiao Yong's improved eyesight, he could only see a little water light here.

The area of the cave is very large, and there are many stalactites of different shapes and colors growing on the roof and sides of the cave.

The stalactites formed on the roof of the cave are dripping and falling water droplets, many of which are connected to the surface of the river above ground or underground.

In particular, several huge stalactite stalagmites connected to the banks of the underground river seem to support the entire cave.

At a vertical depth of nearly four hundred meters from the ground, there are still some unique fish in the underground river, and under Xiao Yong's observation, these fish are not big, and their eyes have completely degenerated, and they feed on catching some algae and small insects in the underground river.

At the bottom of the underground river, there are many mineral sands, some of which are golden yellow, which should be gold sand, but the reserves are very small.

"I didn't expect to casually say that there really is a gold mine here. ”

Driven by the water flow of the underground river, the entire karst cave was not suffocated, Xiao Yong used his divine mind to check the entire karst cave clearly, and entered the land of heavenly machines and began to tinker.

Some beast bones, animal teeth, and some unused ores obtained from the desolate world, especially important, as well as a few pieces of dog's head gold that were much smaller than Xiao Yong's donation to the museum, were gathered together by him and prepared to be taken out and put in the cave.

However, thinking of the large amount of spiritual energy contained in these things, especially the innate spiritual energy that had been infected by the earth for so long in the land of heavenly machines, Xiao Yong prepared to arrange a gossip sealing spirit array in the entire Tiankeng Cave that was the same as the Qinghe spiritual land.

However, this set of formations was different from the Shangqing River Spirit Land, and Xiao Yong was ready to refine it from the Flood World.

Xiao Yong passed through the Heavenly Machine Wall, did not alarm the clansmen of the Xiao tribe, selected some stones from the ground, took them to the Heavenly Machine Land, and began to refine the formation tablet of the Bagua Sealing Spirit Array.

Combined with the stalagmite shape in the Tiankeng karst cave, Xiao Yong changed the shape of the eight array tablets required to arrange the Bagua Sealing Spirit Array, and the gossip runes were skillfully integrated into the texture of the stalagmite formation tablet.

With the Bagua Sealing Spirit Array Tablet and the small stone slab of the Heavenly Machine that had been activated and connected together, Xiao Yong began to arrange them in the Tiankeng Cave.

Arranged to cover the entire Tiankeng Cave Bagua Sealing Spirit Array, Xiao Yong hid the small stone slab of Tianji in a hidden stone cave in the cave, and then took out a large number of various animal bones, ores and other things from the land of Tianji.

A few small pieces of dog's head gold were buried by Xiao Yong in the sand of the river under the stalactites by the underground river.

The aura emitted by these things has increased the amount of the acquired spiritual earth in the entire cave, and the small fish in the underground river can actually feel the changes in the aura and become much more active, and jump out of the water from time to time, as if they want to get close to the aura in the air.

"It's not easy to get down here, I don't know if Zhang Lao and they have given up, but from the confidentiality agreements I signed, that piece of dog head gold must be very important, even if Zhang Lao doesn't come here anymore, other relevant personnel should come to explore this sinkhole and hole clearly. ”

Putting the beast bones, animal teeth, and special ores that looked some years old into a cave on the half wall of a cave formed of stalactites that looked relatively dry, Xiao Yong removed his traces and put away the iron rattan rope.

Taking advantage of the land of heavenly opportunities, he "teleported" to the flat land of Jianzi Peak, and so far, Xiao Yong's trip to the old mountain can be regarded as a failure.