Introduction to the Postal Agency: The exhibition hall of the Hadapu Postal Agency still maintains its original appearance. In September 1935, after the First Army of the Chinese Workers' and Peasants' Red Army arrived in Hadapu on its long march, Comrade Mao Zedong and his guards went to the old Kuomintang newspapers purchased by this postal agency and learned about the existence of the Red Army and the base area in northern Shaanxi. As a result, the important decision to march to northern Shaanxi was made.