Qingdao Haichang Polar Ocean Park
Qingdao currently holds a minimum of three walruses as of 2021; a bull, housed in an indoor exhibit with a seal, and two cows, one with uncapped tusks and one with capped tusks, who perform in an outdoor stadium.
This facility opened to the public on July 22nd, 2006.
On April 21st, 2016, during their tenth anniversary, this facility's name changed from Qingdao Haichang Polar Ocean World (青岛海昌极地海洋世界) to Qingdao Haichang Polar Ocean Park (青岛海昌极地海洋公园).
Qingdao housed a walrus named Badun in 2007. It is likely that this may be the same walrus currently living at Chengdu Polar Ocean Park, considering the apparent age of the walrus at that point and the fact that Chengdu opened three years later. I make this assumption here.
In 2009, a walrus named "Dudu" was mentioned in the media, this being the sole instance I've heard of this animal. A 2015 post by Qingdao stated that they then had two walruses named Atu and Danna. The earliest mention I've found of Atu is from 2013, which stated that she was then four years old and had arrived at the park at a year old; the earliest mention of Danna was in June 2014, which stated that she was then 2.5 years old. In 2016 and 2017 a walrus named Merry was mentioned.
I do not know whether these animals are still alive or whether they are currently still housed at this facility or not.