Step inside an emperor's inner world

Visitors must knock three times before entering the wooden gate. After a brief pause, it creaks open. Standing inside is Qing Dynasty (1644-1911) Emperor Qianlong, the 18th-century ruler whose reign marked the period's height of territorial advantages and cultural confidence. With a slight gesture, he invites his guests to step into the garden he built for his retirement.

The emperor exists only as light.

Digitally projected onto a screen, Qianlong serves as the unlikely host of A Garden Within: An Immersive Light and Shadow Exhibition of the Qianlong Garden, which opened on July 9 at the National Library of China in Beijing. Through holograms, interactive projections and virtual reality, the exhibition offers something even visitors to the Palace Museum still cannot fully experience.

Built between 1771 and 1776, Qianlong Garden, officially known as the Garden in the Palace of Tranquil Longevity, was conceived as a private retreat for the emperor after his planned abdication.