You should not mention any game related stuff in your nominations. Your waypoints may be used in other games with different inclusion rules.
Pokemon Go uses S2 Cells in deciding what can be used at all and when a Gym will be created.
Note: Never misplace a nomination to manipulate the game map. This is abused and could cause warning and / or suspensions (which will be for the games as well as wayfarer).
https://pokemongohub.net/post/article/comprehensive-guide-s2-cells-pokemon-go/
That is one of the joys of wayfaring!
As long as there are people that are allowed in that area and there are no rules / laws regards photography etc then nominations in these areas can be accepted.
- You should not be making nominations on a restricted site unless YOU have the right to be there.
- These areas will commonly get “Property Owner Requests” to have them removed.
If it is an excellent location, and ruined castles usually are, you can submit it anyway. No-one is forced to visit every pokestop/gym. If you can’t take photos though, that’s a problem for lots of reasons.