About 1.7 km. According to Baidu map, it is 1.7 km from Chairman Mao Memorial Hall to the Palace Museum. Walk from the north gate of Chairman Mao Memorial Hall, turn left 20 meters due west, turn right 70 meters, turn left 360 meters, turn right 70 meters, turn left 20 meters under the underground passage, walk 80 meters, turn right 70 meters, turn right 270 meters, turn right 780 meters into Xihuamen Street, and walk 100 meters to the Palace Museum.