Castle of Black Iron
chapter-905

After entering the huge cave for over 10 minutes, Zhang Tie felt a great suction, which was not caused by the air flow but by the changing magnetic fields in the cave. Zhang Tie felt like riding a magnetic elevator. Without using any strength, Zhang Tie had been led and wrapped by that strength and dove towards the underground world as fast as a lightning bolt.

The secret to accessing the earth-elements realm was to stay relaxed. Therefore, Zhang Tie didn't control his body on purpose. Just like flowing towards the lower reach of a river by boat, Zhang Tie enjoyed traversing in the exotic tunnel.

In such a state, Zhang Tie had to be relaxed as he couldn't even move at all. Just like those in a running elevator could not jump out of it, Zhang Tie could not slip the leash of this tunnel either.

Even knights could not disobey the great, mysterious power of the mother nature.

Zhang Tie had read an article in the Mountain of Brightness——even a knight who had formed 4 chakras could not move inside, not to mention a common black iron knight.

Zhang Tie made an attempt and found that even his spiritual energy had been frozen in this exotic tunnel.

After making attempts a few times in vain, Zhang Tie gave up his attempt absolutely.

Nobody knew why there was such a tunnel just like nobody knew why all the planets in the universe were round. This tunnel was as old as this planet. It seemed to be one of the original looks of this world. Just like the sunken part between the upper part and the lower part of an apple, which was carried by most of the fruits, people would think it was determined by genes. But who determined the genes of the fruits? Whether the shapes of fruits were caused by the evolution and duplication of this planet or not?

After the Catastrophe, the magnetic poles of this planet rotated, causing great changes. After the thick ice layer and snow completely melted, this tunnel was exposed. Before the Catastrophe, this place was not called Force Province; instead, it was one of the poles of this planet. The greater part of the Eastern Continent were polar regions before the Catastrophe.

...

In this tunnel, Zhang Tie felt being still as the relative distances between him and the other knights and airboats remained unchanged. Everyone seemed to be still. However, in such a relative still state, everyone could see exotic lights rushing towards them and penetrating through them in a split second from the underground world...

Due to the super high speed, Zhang Tie could not see clearly the surrounding scene at all. All the surrounding scenes became shadow and light.

Zhang Tie tried his utmost efforts to look around by concentrating his spiritual energy and consciousness a few times and felt that he was penetrating through a hollow layer being filled with lightning bolts which were as thick as hundreds of miles. Zhang Tie was confused why there were lightning bolts underground.

It took him dozens of seconds to penetrate through the layer being filled with lightning bolts as thick as hundreds of miles.

Besides, Zhang Tie saw some other strange things during this period...

Time in this tunnel seemed to be slower than that outside...

Whether it was in the Dragon Cave or in the tower of time which Zhang Tie discovered beneath Kalay Mountain Range, theoretically, they were both in the earth's crust or being close to the earth's crust and earth mantle. However, Zhang Tie reached the most mysterious internal region of this planet, which was in the depth beneath the earth's crust.

The journey lasted over 3 hours. Zhang Tie didn't know how many miles had he dived. All of a sudden, he slowed down. After another 10 minutes, everybody felt relaxed while the binding force from the tunnel suddenly disappeared. At the same time, all the knights and airboats recovered their maneuverability and stabilized themselves.

They were then blown into a vast space by the heavy air flow.

What entered Zhang Tie's sight was the red clouds at the dome of this space. There were undulating mountains below the clouds. Right on the horizon in the distance, Zhang Tie caught sight of looming lamplights.

All the airboats and knights were flying towards the lamplights in the far, followed by Zhang Tie leisurely.

When he drew close to the lamplight, Zhang Tie found that it was a huge fortress which was much more magnificent than a Class A city on the ground.

It seemed that the fortress had been standing there since ancient times as it carried a time-honored yet mysterious qi.

The walls of that fortress were as high as thousands of meters. The entire fortress was composed of many stories covered tens of thousands of square miles in a key region. Zhang Tie could not even see its border. There were various, dense high pagodas in the fortress, which looked like spines on a hedgehog. Pointing at the sky one after another, they were very terrifying.

This fortress could never be built by humans. Because the entire fortress, including the pagodas inside it, was shining metallic luster. It was completely composed of metal.

Until today, people could still not accomplish such a magnificent, metal fortress covering tens of thousands square miles even after combining the scientific abilities of humans before the Catastrophe. It was completely out of people's imagination.

Zhang Tie even doubted that the total of steel storage among all the Class A cities in Taixia Country would not match that of this fortress in weight, not to mention building it.

Humans in this age or before the Catastrophe could never build such a magnificent complex.

Undoubtedly, this fortress was a prehistorical relic in the earth-elements realm. It was left by a far-ancient civilization.

There was the highest metal pyramid in the center of the fortress. The mysterious and borderless world——Earth-elements Realm was facing this fortress in the far.

This was the Lion Fortress, the most magnificent human fortress, the prototype of human battle fortresses in this age and the firmest fortress of humans across the entire Eastern Continent and Taixia Country in the underground world. It was both the portal for humans to enter the Earth-elements Realm and the throat from the Earth-elements Realm to the Eastern Continent.

If this firmest fortress and shield was broken through, it meant that the contingent of demons would directly appear on the ground of Eastern Continent and attack the core region of human countries. On the opposite, this fortress would also serve as the firmest bridgehead for humans to explore the underground world.

From a certain perspective, the Lion Fortress was the beacon of hope that encouraged humans to defend demons.

This was the world and the battlefield of knights!