People in lines enter the Hall of Martial Valor in Beijing's Palace Museum on Sept 8, 2015. [Photo/Xinhua]

People in long lines waited to enter the Hall of Martial Valor in Beijing's Palace Museum, also known as the Forbidden City, on Tuesday. But that was to be expected.

The best-known scroll painting in Chinese art history－titled Along the River During the Qingming Festival－was completely unrolled for the first time since 2005.

The work by Zhang Zeduan (1085-1145), measuring 24.8 centimeters wide and 5.29 meters long, depicts a flourishing landscape in Bianjing, the capital of the Northern Song Dynasty (960-1127). Bianjing is today's Kaifeng in Henan province.

The scroll is only part of the special exhibition titled The Precious Collection of the Stone Moat, which includes 283 ancient paintings and calligraphy masterpieces once recorded in the Qing Dynasty emperors' catalog. The display is a main event celebrating the museum's 90th anniversary since opening to the public.