<P> "The March of the Volunteers" </P> <P> The Sino - Japanese conflict (1931--45) gave the Great Wall a new lease of life in the eyes of the Chinese . During the 1933 defence of the Great Wall, inadequately - equipped Chinese soldiers held off double their number of Japanese troops for several months . Using the cover of the Great Wall, the Chinese--who were at times only armed with broadswords--were able to beat off a Japanese advance that had the support of aerial bombardment . With the Chinese forces eventually overrun, the subsequent Tanggu Truce stipulated that the Great Wall was to become a demilitarized zone separating China and the newly created Japanese puppet state of Manchukuo . Even so, the determined defence of the Great Wall made it a symbol of Chinese patriotism and the resoluteness of the Chinese people . The Chinese Communist leader Mao Zedong picked up this symbol in his poetry during his "Long March" escaping from Kuomintang prosecution . Near the end of the trek in 1935, Mao wrote the poem "Mount Liupan" that contains the well - known line that would be carved in stone along the Great Wall in the present day: "Those who fail to reach the Great Wall are not true men" (不 到 长城 非 好汉). Another noteworthy reference to the Great Wall is in the song "The March of the Volunteers", whose words came from a stanza in Tian Han's 1934 poem entitled "The Great Wall". The song, originally from the anti-Japanese movie Children of Troubled Times, enjoyed continued popularity in China and was selected as the provisional national anthem of the People's Republic of China (PRC) at its establishment in 1949 . </P> <P> In 1952, the scholar - turned - bureaucrat Guo Moruo laid out the first modern proposal to repair the Great Wall . Five years later, the renovated Badaling became the first section to be opened to the public since the establishment of the PRC . The Badaling Great Wall has since become a staple stop for foreign dignitaries who come to China, beginning with Nepali prime minister Bishweshwar Prasad Koirala in 1960, and most notably the American president Richard Nixon in his historic 1972 visit to China . To date, Badaling is still the most visited stretch of the Great Wall . </P> <P> Other stretches did not fare so well . During the Cultural Revolution (1966--76), hundreds of kilometres of the Great Wall--already damaged in the wars of the last century and eroded by wind and rain--were deliberately destroyed by fervent Red Guards who regarded it as part of the "Four Olds" to be eradicated in the new China . Quarrying machines and even dynamite were used to dismantle the Wall, and the pilfered materials were used for construction . </P>

When was the first section of the great wall built