Set in a fictional southeastern European country, and you see some domed buildings from time to time but no Orthodox temple. As far as I can tell, the drama avoids any mention of religion or religious differences between the peoples of said fictional country. (Though its population appears to be rather diverse.)
In the latest episode the Song Hye Gyo's character refers to the domed building as a chapel. I don't remember any interior shots of this "chapel."
Time to go, Theresa
1 hour ago