In 2015, the administrative office of the palace set up a team to be responsible for the reclamation of relics, and collect items from building walls and foundations in the area.

"Actually, the reclamation work had already begun in the 1980s. But it is difficult to recover these historical objects because they have been integral parts of local residents' houses and we can only reclaim them after the buildings are torn down," Chen said. "Thankfully, we have enjoyed great support from the residents."

She recalled one man who brought several bricks engraved with inscriptions of the palace to the office and then drove a few people to the site where he had found them.

"The stones and bricks may not be as impressive as looted artifacts, but we are obligated to retrieve all relics, whether they are precious pieces taken to foreign countries or ordinary bricks that were once part of the palace. Even a brick that has no exquisite engraved pattern belongs to the palace and reflects its history."

Some of the reclaimed items, such as the tiger-skin jade, have been repaired and used in the palace restoration project.

Reclaimed items are stored in two warehouses at the palace complex, in addition to those on display. New exhibition zones for these items are expected to open to the public within the year.

Cheng Si contributed to this story.