[A Gentleman's Dignity] Kim Jungnan at Marriott Executive Apartments Yeouido Park Center

korean drama shooting location
second photo from Marriott's Official Website

Marriott Executive Apartment Yeouido Park Center
Yeouido-dong, Seoul 150-881 South Korea

So I am not entirely sure if this is the same apartment which Kim Do Jin refers to as their office residence; but yeah, the hotel where Minsook had mistaken Yisoo as Rok's mistress is a serviced apartment located just a few stone throws away from Han River in Yeouido. 

For more information, visit the official website.

But if you are into hotel promotions, better check THIS SITE now. Maybe they have deals with Marriott. :)

Oh, and for Filipinos... A Gentleman's Dignity will be aired on ABS-CBN starting November 19. I'm not sure about the time slot though.