Yesterday someone gave me some information on my FB page, this place where Eun Tak accidentally summoned Kim Shin is located at Seong Su Dong. And it looked like a very interesting district!
(Pic Cr: tvN/viu)
The location is at the arrow in the map below, you can walk there from Seongsu Dong Exit 4.
There is a Mocha Study here in this place before for a limited duration, it is closed now.
When I was googling about this area, I found that this area is named Brooklyn of Seoul, it is a place converted from industrial area to an interesting artistic area with lots of special small shops and cafes. Seoul Forest is also quite close by and Eungbongsan Mountain where night view of Seoul can be seen. (Eungbongsan Mountain is filming location of Another Miss Oh.)
(map from daum)
-Please include link to my FB/blog if you are reposting this somewhere else.