Second, even if you go back to the Heian period when there were palaces galore, 宮 is used as a suffix, and it's pronounced ぐう, as in JermaineGUU (Jermaine's Palace). But in people's names, it's pronounced MIYA, and in NON-place-name jukugo it's KYUU. What the palatial fuck!
My bad, I guess the Emperor's house is technically a 宮.
But even then (or at Versailles, for that matter!) a Japanese tourist would never say "Hey Mieko! Get a load of that classy MIYA!"
So, in short, the KUNyomi is only used in people's last names, and the only useful ONyomi (きゅう) is actually an exception - all the other (useless) jukugo use ぐう.
Aren't you glad you're learning Japanese now?
That's a CUTE palace you got there. All those cherubs in the cornices!
The princess left her crown in the washtub at the palace.
never used, except in last names, like Karin Amamiya, the labor rights activist.
The federal government is run by BEURACRATS.
There's a WASHTUB in the damn palace.