A lot of has to do with the moon like I am the only one to venture so far could be Eros when she went into Croats end and when it says I have been gutted i think it means how the moon has been hollowed out and when it says about freedom but it's now a reminder of slavery it could be talking about how the moon was a place we discovered and we took control of it but then the hive took over and enslaved it.

Well he has already said its not the moon but I do agree it has to be something specific about it

Might have to do with the taken King? Once you enter my domain... Maybe it's somewhere we've never been to before