That giant palace is obviously the Hagia Sophia in Istanbul. For millennia it was a Christian church but in the fifteenth century it was captured by Muslim armies who turned it into a mosque and added the minirets.
@Rukja
It's a typical trope. A person said this character but nobody is found. Besides, I think her friend was sent to death but wasn't executed to death.
P22-23:
A chokehold seems incredibly dangerous to pull off against someone wearing that kind of spiked crown/headdress, especially if you have huge anime eyes.