Liu Tan doesn't really have a very organized approach to things, and most of the time he just does whatever he wants.

This time was the same. After he had this idea, he felt that this idea was a bit unreliable.

A water park should first have water. The Northern Country does not lack water, but it lacks clean water sources.

Because Liu Tan wanted to build a water park, there must be water slides, and some other water projects. In short, the project will definitely be quite large.

He listed the preliminary goals on paper, planning to divide them into water play area and in-water play area.

The two areas are not interconnected, and water activities mean taking a boat to admire waterscapes such as lotus flowers, so the pool must be purely natural.

As the water quality in the water play area needs to be clean, it is best to build a swimming pool directly.

But these two have to be treated as a whole. Liu Tan calculated that, not to mention anything else, it would probably take a month to build these two pools. Even if other things were manufactured simultaneously, it would not be completed in a month.

He sighed deeply: "Why didn't Father come later?"

He even began to consider whether he should write a letter to Liu Che to ask him to come later.

Zhu Shan, standing by, saw Liu Tan's frown and whispered, "Your Highness, don't worry. His Majesty will only be traveling in mid-April. It will take some time to get from Chang'an to the capital, and Tongda City is on His Majesty's itinerary. Your Highness can arrange for His Majesty to travel somewhere else first while we start construction here."

After hearing this, Liu Tan suddenly realized, yes, he didn't need to prepare everything before Liu Che came, as long as he could let Liu Che have fun, it was fine, this was not the Changshou Palace.

Liu Tan patted Zhu Shanfu's shoulder with satisfaction and said, "You have a bright future, young man."

Zhu Shanfu was at a loss whether to laugh or cry. He was much older than Liu Tan, but he found it quite cute to see his own prince pretending to be old-fashioned.

According to what Zhu Shanfu said, Liu Tan calculated the time and found that if he calculated it according to Zhu Shanfu's way, he would have plenty of time, and there was no need to combine the two water activities together.

Because it is easier to watch from the water than from a swimming pool.

After making up our minds, we started designing like crazy, starting with the water play part.

For water activities, you definitely need a boat. In fact, the Han Dynasty's shipbuilding has developed quite well. At least it is not a problem for Liu Tan to build a cruise ship. A flower boat has at most two floors, and then you can add more windows and inlay them with glass.

He didn't have to worry about the boat trip, he could just give the order casually.

The activities that require the most of his attention are actually those that involve water activities.

First of all, he had to solve the water quality problem. It was impossible to use groundwater for the swimming pool. Water had to be drawn from the Yellow River, so water filtration was necessary.

After much deliberation, Liu Tan finally chose the location at the foot of Yangshan Mountain. First of all, the river water here does not pass through the Loess Plateau, so it does not carry a lot of silt, so it is easy to filter.

Because Liu Tan didn't have any particularly good filtering methods, he could only use a relatively sparse gauze to filter it simply and roughly, and he also had to prepare multiple filtration methods.

The first filter uses a sparse fishing net to catch the fish and aquatic plants in the water. The second filter is a denser one to block smaller aquatic organisms. Then from the third filter onwards, the mud and plankton in the water are filtered.

Of course, it is not easy to deal with plankton, as there will always be some microorganisms present. But it doesn’t matter, he will also disinfect the water in the swimming pool with alum.

This way, at least the water quality can be guaranteed to be clean to the greatest extent.

Just as Liu Tan was about to mark the land on the map, he suddenly remembered his passive "golden finger". After a moment of thought, he handed the map to Zhu Shanfu and said, "Choose a place at the foot of Yangshan Mountain. I want to use it to build a pond."

He didn't want the entire project to be forced to terminate because of the discovery of the mine. He would have no place to cry at that time.

Zhu Shanfu was a little confused and didn't understand why his highness wanted him to choose, but he thought of the fact that his highness the King of the Northern Territory had been preparing to receive the emperor.

Even though he didn't know what this place was used for, he instinctively wanted to choose a place with beautiful mountains and rivers.

Before coming here to take the imperial examination, Zhu Shanfu had traveled extensively, and he had indeed been to the foot of Yangshan Mountain. Recalling the scenery there, he carefully chose a spot and said, "Your Highness, the scenery here is quite good. You can see the mountain, but it's not too close to the mountain."

After all, there is the Great Wall above Yangshan, which means it is too close to the Huns, which is not good.

Liu Tan gave him a look that said he was very smart and initially chose this place.

Then he designed the shape of the swimming pool. Since it was not used for competitions, the shape of the swimming pool did not need to be square like in later generations. So he was playful and made it into the shape of a panda's head.

One of the panda ears is a shallow area for entering the water, and the other is where the slide is placed.

There were no slides in those days, so Liu Tan was more cautious. He asked someone to make a model first, and then did some experiments bit by bit to see what height would produce splashes when entering the water but not be so exciting.

He didn't dare to set his sights too high. If something went wrong, he would be condemned as a sinner for all eternity.

Anyway, it's just for fun. If there is no such thing in these days, then Liu Che will not think it is not exciting enough.

In fact, Liu Tan hesitated for a long time between the slide and the chute.

The difference between a slide and a tubing slide is that one is driven by water on a boat and slides from top to bottom into the pool, while the other is to slide in by yourself.

In the end, he thought about it and decided to try both.

However, the slides in later generations used single-person boats made of rubber. Since there was no rubber in those days, the only option was probably kayaks.

As for the materials of the slide, Liu Tan thought for a long time and finally decided to make them different. The slide would be made of wood, polished, and then painted with varnish.

After all, you may not be wearing any clothes when you are riding on the slide, so you should try your best to ensure that there will be no accidents that may cause injuries while sliding down.

The angle of entry into the water was also determined after model experiments.

Of course, this cannot be used as the final basis, so Liu Tan asked someone to build a slide next to his pool, and then asked people to conduct experiments. After ensuring that there were no mistakes, he asked people to make a slide of appropriate height.

As for the waterproofing of the wood, Liu Che will only stay here for three months at most, so as long as the slide is in good condition within three months, it will be fine.

After three months, the pool will be empty.

Liu Tan himself had no interest in going there to play. He was so busy that he had no time to play there.

So this slide is basically disposable. If it were in the past, Liu Tan would have thought it was too luxurious.

Now... forget it, let him be extravagant. At least he can give the people some work to do. Otherwise, the money will be too big to fit in the warehouse.

After the slide was completed, the next step was the slide. The slide was different from the slide because it spiraled down from a high place, so it had to be stronger. Liu Tan simply used a stone slide.

We still didn't dare set the height too high for fear of accidents, and then we laid an interception net outside the slide so that even if someone falls from it, they will land on the net and avoid injury.

Because the spiral descent also has a certain acceleration, Liu Tan thought about it and decided to add a little excitement - he made a small ramp before entering the water at the end, and used the acceleration of gravity to let the kayak rush up the ramp, and then slide rapidly down the ramp into the water.

This should make Liu Che find it interesting.

In fact, the slide and kayak are not difficult to solve. The only difficult problem is the water flow inside the slide.

Because of gravity, it is impossible for water to flow from low places to high places, so how to transport the water up becomes a problem.

Miao Rui couldn't help but smile when he saw Liu Tan looking worried. "Your Highness, don't worry. We can just do the same thing here as we do at the coal mine."

Liu Tan shook his head. "It's different. Not to mention the small amount of water being transported there, the equipment itself is also a bit too ugly."

Miao Rui shut up decisively. This was a playground designed for the emperor, so of course there couldn't be any ugly things there.

But if we don’t want to see any ugly things, do we have to rely on manpower to lift the water up?

Of course, Liu Tan would not be so cruel, and the efficiency of manual water pumping was too slow, probably not enough for fun.

He thought for a moment and wrote two words on the paper: waterwheel.