everything is well done in this drama, the acting, the plot, the music !
2 Korea, one kingdom, one republic, and a way to go from one to another world.
The story is very well built, when you re-watch it you see how thorough it is.
The OST is one of the best i know for a series, always a pleasure to hear.
The casting is great, the 6 main roles are absolutely perfect. The chemistry between the FL and ML is good, but also the Bromance between Lee Min-Ho and Woo Do Hwan, and the "more than friendship" relationship between Kim Kyung Nam and the FL. The prime minister is very well played as well.