Sun Yat-sen wanted to change the Gate of the Great Qing Dynasty to the Zhonghua Gate, but after the plaque was removed, he looked at it upside down, but said that he would not change it
In some ancient film and television dramas, when the enemy invaded their own homes, some soldiers would swear an oath to "swear to kill the enemy and stay outside the enemy's national gate" to express their morale to defend their homes and defend the country. Then you are wrong, the gate here is actually the main entrance of the Forbidden City.

This gate was known as the first gate of the imperial city during the Ming and Qing dynasties, that is, the Daming Gate at that time. This door has a total of 3 doors, which are usually closed. It would only be opened when the Emperor needed to go on a tour, and the middle door of these three doors could only be passed by the Emperor, and others who wanted to pass through could only enter and exit through the side doors on both sides. Even civil and military officials could only pass through the doors on both sides every day.
And all officials and generals had to disarm all their weapons as they walked through this gate before they could go to see the emperor. The army stationed here is the famous forbidden army, in addition to the emperor, there is actually another person who can pass through this gate, this person is the empress.
If there is a door, there will be a plaque, which is an inevitable part of ancient architecture, equivalent to the eyes of ancient architecture. It is often hung at the top of the door for decoration to reflect the name and nature of the ancient building. The Great Qing Gate naturally also has a plaque, in the Ming Dynasty, it was called Daming Gate, and the plaque was Daming Gate. In 1644, Li Zicheng entered Beijing and changed the Daming Gate to Dashun Gate, because it took time to make the plaque, but Li Zicheng did not wait for the day when the plaque was completed before exiting Beijing, so there was no time to officially change the name.
In the early days of the Republic of China, the "Great Qing Gate" was renamed "Zhonghua Gate" during the celebration of the first anniversary of the Xinhai Revolution. Since the name was changed, the door plaque must be removed and re-completed, the original door plaque is made of stone, in order to save costs, after consultation, everyone decided to carve the "Zhonghua Gate" 3 words directly behind the "Great Qing Gate" door number, in this case, there is no need to rush to make a new door number, just the other side of the carved word hanging up.
Unexpectedly, after turning over the stone plaque, everyone was shocked to see the other side, they saw the three words "Daming Gate". That is to say, the method of saving that craftsmen have come up with now, the Qing Dynasty craftsmen more than 200 years ago have thought of, and their wisdom is the same, which is really shocking. In the end, the craftsmen could only make a wooden plaque to hang on it. Now the "Zhonghua Gate" no longer exists, and the original "Daming Gate" and "Great Qing Gate" door plaques are also placed in the museum.