Fang Yuan paid two hundred Yuan Stones and entered the inner city together with Bai Ningbing.
Although the inner city was built inside a mountain, its streets were wide enough for ten carriages to travel abreast.
Once they entered, the flow of people dropped sharply to less than half that of the outer city.
However, Gu Masters could be seen everywhere — First Transformation Gu Masters walking about in droves, Second Transformation Gu Masters mixed among them, and occasionally one or two Third Transformation cultivators.
Ordinary mortals were extremely rare. After all, entering this place required a hundred Yuan Stones per person. Even many Gu Masters who had personal servants attending them were unwilling to spend that money recklessly.
The inner city's illumination primarily used a type of fuel called fire coal stone.
Fire coal stone burned for a long time and produced no smoke. Every hundred steps that Fang Yuan and Bai Ningbing walked, they would see a hollow carved into the wall with a pile of fire coal stone burning inside.
Though the heat emitted by fire coal stone wasn't high, the sheer number of them burning continuously still raised the temperature of the air inside the inner city and made it dry.
Unlike the outer city, where all sorts of buildings stood in a chaotic jumble, the buildings here had been unified in construction. They shared similar exteriors, all built from heat-resistant red rock.
Various branch paths extended outward from both sides of the main streets.
At the same time, every five hundred steps along the street, an enormous cylindrical pillar appeared.
Spiraling stone stairs were carved into the surface of each pillar, winding upward around it, with railings along the outer edge of the stairs.
Through these stairs, people could reach the streets on the floor above or the floor below.
The inner city was not a conventional city in the ordinary sense — it was three-dimensional. From top to bottom, countless streets and densely packed buildings interconnected, forming a network that reached in every direction.
Fang Yuan and Bai Ningbing continued deeper into the mountain. This was not yet their destination.
At a certain point, another checkpoint appeared.
The Gu Masters guarding it had higher cultivation and the defenses were far stricter.
"Please stop, the two of you. Do you have tokens?" The guard blocked Fang Yuan and Bai Ningbing.
The Shang Clan issued tokens of various clearance levels to people of different statuses.
"This is our first time here," Fang Yuan said.
He naturally had no token.
"In that case, please pay two hundred Yuan Stones per person," the guard said.
Fang Yuan handed over the Yuan Stones, and the guard let them pass.
The two thus arrived at the Fourth Inner City.
Shang Clan Mountain had undergone thousands of years of development by the Shang Clan. The entire interior of the mountain had been transformed — tunnels carved out, structures sculpted, and districts laid out in an organized fashion.
As a result, the inner city was enormously vast, divided into five districts from the innermost to the outermost.
The First Inner City, also called the Central Inner City, was the political center of the Shang Clan and a key military stronghold.
The Second Inner City, informally known as the Family City, was reserved exclusively for members of the Shang Clan's main bloodline.
The Third Inner City had an elegant environment and fresh air — it was the high-end district.
The Fourth Inner City was the mid-range district. The Fifth Inner City was the low-end district.
Beyond those lay the outer city, where the flow of people was immense and goods were loaded and unloaded. Compared to the inner city, its management was rather chaotic.
This architectural structure was reminiscent of termite mounds on Earth.
Termite mounds ranged from four to ten meters tall, with entire colonies living inside, their tiny tunnels interconnecting in intricate and elaborate patterns.
The moment the two entered the Fourth Inner City, they immediately felt the air grow humid and the temperature drop.
The Fourth Inner City was a full tier above the Fifth Inner City, and this was reflected not only in the entrance tax being doubled, but also in every aspect.
First, the lighting no longer relied on cheap fire coal stone. Instead, large quantities of a First Transformation grass Gu were cultivated.
They were called Moonlight Ivy.
These vine-leafed plants clung to the walls of the tunnels lining both sides of the streets, spreading outward and visible everywhere.
Their stems were deep blue, and their leaves were broad and large, emitting a faint, pale blue moonlight. Along a single stretch of tunnel, there were tens of thousands of leaves, their soft blue light forming a continuous, unbroken glow.
Because of the abundance of vines, the air here was humid with moisture permeating everywhere. Near the ground, it settled and condensed into mist.
The moonlight refracted through the mist, creating an ethereal haze of light that enveloped everything. Walking along the streets gave one the illusion of strolling through a celestial realm.
The buildings here featured carved decorative patterns, artificial lawns, ornamental pots, and occasionally even artificial rockeries and pavilions.
The pedestrians on the road were even fewer.
Second Transformation Gu Masters had become the mainstream. After all, for a First Transformation Gu Master, the entrance fee alone — two hundred Yuan Stones — was already a massive expenditure.
The most noticeable difference was that walking through the Fifth Inner City, the streets were still noisy. But here, it was far more tranquil.
The two continued deeper into the city until they reached the gate.
"Without tokens, if you wish to enter the Third Inner City, you must pay six hundred Yuan Stones," said the leader among the guarding Gu Masters, who was already at the Third Transformation.
Fang Yuan paid the Yuan Stones and finally arrived at the Third District.
This place was different from the Fourth Inner City once more.
All the building stone here was made from star stone.
This type of stone was a widely used auxiliary refining material among Gu Masters, capable of emitting brilliant starlight in darkness.
The entire Third Inner City was constructed with star stone. Not only the buildings — even the streets were paved with slabs of star stone.
Looking out, starlight stretched in an unbroken expanse, the view clear and unobstructed, no longer hindered by any haze of light.
The air was also wonderfully crisp and fresh. Everywhere one looked, there were pavilions and towers, red walls and green tiles. Bamboo groves and famous trees had been transplanted here, artificial rockeries constructed, and even spring water channeled in to create babbling streams.
The streets were sparsely populated, quiet and pleasant — like a palace among the stars.
"Truly wealthy beyond measure..." Bai Ningbing made a rough mental estimate. The cost of the facilities visible in just this immediate area alone was a staggering figure.
The Shang Clan was the wealthiest power in the Southern Border. Some said that even pulling a single hair from their leg would be thicker than another person's waist. While that was an exaggeration, it wasn't entirely unfounded.