Introduction to the Warning Bell: The Warning Bell is made of copper with a diameter of 1.2 meters, a height of 2 meters and a weight of 1.5 tons. It is located in the northwest corner of the Sun Yat-sen Memorial Hall. On it is inscribed Dr. Sun Yat-sen’s famous speech on the awakening of the Chinese nation in 1924 and His handwriting of "progressing together to achieve great harmony". The warning bell was cast not only to commemorate Sun Yat-sen's life of trying to awaken the Chinese nation and revitalize the motherland, but also to continue to alert the people to strive to build a unified and prosperous motherland.