In other words, it's real, but it isn't. A place where... everyone's shared memories make up the dream? Memories of whatever the real Yharnam may be.

[ The way she spoke, it at least sounded that way, but it was hard to parse. Probably just as hard for her. ]

...Then the hunt was still going, before you arrived here. [ That's... a sobering thought. Would Anna go back to the Hunt after getting out of Hell? Talk about a curse. ]