In the ancient Chinese woodworking industry, there was a technique called Luban lock, commonly known as mortise and tenon sunou.
When building pavilions and pavilions at that time, carpenters who knew this skill would dig grooves or make flanges at both ends and in the middle of the building timber, and then splice the timber piece by piece in an orderly manner according to the needs of each part on the drawing.
Assembling them is like building blocks, adding up layer by layer to build a building.
The entire building does not need a single iron nail to fix it, and it can still be extremely strong and stand firm.
It's a pity that this unique skill has been lost long ago, and is replaced by reinforced concrete, stones and bricks.
At that time, carpenters in neighboring Japan also used this method to build buildings, but the name was different.
Among the buildings built using this technique, the most outstanding one is Azuchi Castle, the residence of Oda Nobunaga, a powerful figure during the Warring States Period in Japan.
This Azuchi Castle is located in Azuchi, Shiga Prefecture, Japan.
The entire city is built on a mountain top more than 100 meters above sea level.
It has seven floors from top to bottom and a total height of 65 meters.
A wide avenue was built under the city, with residential houses, temples and military commanders' residences built on both sides of the road.
Since Oda Nobunaga was very fond of Western Catholicism in his life, he built an attic on the top of the tower, and Oda Nobunaga himself named it "Tenchudai".
The entire city is mostly made of wood, and it is built in the form of mortise and tenon without any nails or rivets.
It is said that at that time, Oda Nobunaga selected architects to build the city from all over the country, and outstanding craftsmen from all walks of life came to apply for the election.
In the end, Oda Nobunaga chose an unknown rural craftsman to build Azuchi Castle.
It was originally calculated that it would take five years to build the castle, but Oda Nobunaga insisted on shortening the time to three years.
In the past three years, more than 100 billion taels of gold were spent to build Azuchi Castle, more than one million craftsmen were employed, and more than 40,000 trees were used.
The main beams were as old as 2,500 years old.
Long.
But after it was built, Oda Nobunaga only lived there for less than three years before he suffered the Honnoji Incident and died in a foreign land.
Azuchi Castle was also destroyed by fire.
The most famous city in Japanese history disappeared.
But there is another completely different theory among Japanese people about the disappearance of Azuchi Castle.
According to legend, when Oda Nobunaga attacked Mouri, Takeda, Uesugi and other heroes, he killed wantonly and accumulated many grievances. countless.
So after it was built Azuchi Castle, all the evil spirits gathered here and cursed Oda Nobunaga himself and this luxurious and magnificent city.
In the end, they not only took away Oda Nobunaga, but also turned Azuchi Castle overnight.
There is no trace of him.
To this day, some people still regard this lost ancient Japanese city as a "ghost town
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