1. Can you please check what's definition of a `=recreation_ground` first? I'm already using the loose definition. The strict definition is a grassy area, which this doesn't qualify either. You can already see from imagery it has 2 parts, not one area. Parks, at least in HK, doesn't have that much green space  when hard courts are used, but those are still open space.  
2. Can you clariy what you mean by "the compound"? It's rare for a small outside part to be access-controlled alone on its own. 
3. What "local property website"? Indeed, I have to conclude you have no knowledge and awareness on this topic, and guessed what it is. But actually anyone could have seen it's obviously a a very low quality website, with suspicious data source, which you can't copy directly and wholly from government data either. Again, the website has "all rights reserved", meaning you can't immediately safely copy from it as well. 
4. Of course, I have to assume you guessed this for some reasons. "Sitting-out area" is the very textbook and awkward naming by government given to a very specific government facility type, which exactly has little open space, and at least more vegetation than this. They are gazetted and listed in the law. It's almost impossible for them to be named from a building. It's also not "休憩地方", but "休憩處“, if you can really read Cantonese, and know how they are named in HK. Lastly, yes, it's an quite obvious thing to assume someone who have edited all over the world in other countries may not have local knowledge, as compared to someone who have edited much here. 
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