Oh, it's possible that this is a plaza, looks intricate from atop (Bing); I think it's still getting set up on those images. Access via the two eastern flights of stairs was still fenced off (coming from the public path by the elevators) and is semi-permanently fenced off by a permanent steel fence/gate that cordons off access to all entrances on the lower, eastern facing side but I'll take a closer look next time I'm in the area.

Thanks for laying out the two ways to do it! Option one is pretty much what I have done for now (one single shape encompassing both buildings ("building") as well as individual "building:part" shapes for the southern and all northern buildings). With that plaza being a plaza though, it might be better to go with option two, have two separate buildings and their individual, respective parts, the plaza and then a relation, as you suggest, to group them all into the art gallery entity; I think that's what I'll do, good solution and seems like the proper way to do it.

Thank you. I'm not sure about that flight of stairs leading up the rocks from the southern end of Lincoln Crescent; will have to check that out as well. I hope it still exists!