Could these be some clues? (lightly spoilers)

[怎么会是呢]

While wandering around the estate, I noticed some interesting patterns under a birdbath near the cliff. It consists of two circles of black, white, and gray tiles, with 8 tiles in the inner circle and 16 tiles in the outer circle.
https://steamcommunity.com/sharedfiles/filedetails/?id=3475254664
The patterns remind me of "The Sacred Circle" in the bottom right corner of the world map in the classroom . I can see there is some similarity between them, but I don't know yet if this will be a useful clue.
https://steamcommunity.com/sharedfiles/filedetails/?id=3475270907

Likewise, in the underpass of the estate , each crescent shaped steel beam is adorned with a certain number of circular small iron sheets , seemingly conveying some information, perhaps numbers or orders?
https://steamcommunity.com/sharedfiles/filedetails/?id=3475252860