'Minimum intervention'

Wang, former director of the cultural relic conservation department at Nanjing Museum, has about half a century of experience in repairing ceramics and glazed glass. The styles of the glazed tiles of Yuanmingyuan shared similarities with those in the Forbidden City, he said.

Wang said traditional craftsmen should be able to produce new components to replace some missing parts to maintain the look of the relics.

The principle of "minimum intervention" has been adopted and signs of such restoration would be recognizable and reversible, Wang said.

In May 2019, a program called Restoring 1860 began in Yuanmingyuan to bring new life to broken pieces of unearthed relics. The glazed tiles' restoration is part of the third and largest phase. It also includes 24 unearthed imperial porcelains, including cups, plates and bowls used by the Qing royal family during reigns of emperors Kangxi (1662-1722) and Qianlong (1736-95).

Wang said the toughest job is picking out the broken pieces that once belonged to one item among a myriad unearthed ceramic pieces. Over 100,000 porcelain pieces of over 20 kinds have been unearthed from the ruins. To put one bowl together, restorers sometimes have to search among hundreds of pieces discovered in one spot.

This year, the 160th anniversary of the palace's destruction, is a pivotal moment for the revival of Yuanmingyuan.

This month, a famous bronze horse head sculpture looted from the Xiyang Lou area by Anglo-French forces and taken overseas was finally returned to Yuanmingyuan.

"Behind each broken piece of cultural relics, there is a broken piece of history," Chen said. "We cannot fix the past and fully display the splendor of Yuanmingyuan again, but we can study conscientiously and fix the cultural relics for our memory and our future."