Apart from Hongkong and Taiwan Province, what land ceded since the end of Qing Dynasty has been recovered?

The (partial) recovery of Heixiazi Island in Heilongjiang Province is a matter of recent years, which can be found in Baidu official information, which was reported by CCTV and newspapers before.

Everything on Heixiazi Island is so similar to that of Sanjiang Plain: it used to be a sub-island of the "Great Northern Wilderness", and it was a fertile land. It was originally connected with the mainland of Sanjiang Plain, but later it gradually moved away from the mainland and became an island due to the erosion of the two rivers.