Maybe I have been to Naksan Park for too many times, so I recognised it immediately when I saw some of the scenes with the Seoul old city walls. You can walk up there from Hyehwa or Hansung University Station. Highly recommend going to Naksan Park at night! Apart from seeing the night view of Seoul, you can see the old city walls at night, which is a really pretty sight.
I saw someone mentioning about going to Bong Soon’s home online, so I went to ask and was told that it was the same place as Park Shin Hye’s home in Doctors, right in Ihwa Mural Village, which is also close by at Hyehwa Station.
Depending on your itinerary, if you want to see the murals, you can start from Hyehwa in late afternoon and walk up slowly and then you will be able to see sunset and the city walls at night before walking down along the walls to Hansung University Station.
If you are going at night, then walk up along the city walls from Hansung University Station (it is less likely to get lost at night this way), and then walk down on the other side to Hyehwa station, then you can go shopping or eating around Daehakro area.
17年4月中再去了一次後的更新 Update after going there again mid April 2017
Her home is back to its original color very quickly after the drama ended. I went just a week after the drama ended. The directions online are not very clear, so I have taken a pic of the map, it is the place with a red circle. Or you can go follow the directions of the map when you arrive, this place is Ihwa Village Museum.