Introduction to the Preface Hall: The Preface Hall is majestic, profound, and has a strong artistic impact. The red wall on the front echoes the black base below it, implying that the heroic Northeastern Democratic Alliance Army fought four battles and drew four draws on the fertile black soil of Northeastern China. Mao Zedong's handwritten message is engraved on the top of the red wall: "Turn Siping Street into Madrid", which exaggerates the extraordinary nature of the Battle of Siping Street.