Seoul Sub→urban is a blog written by freelance writer Charlie Usher and...pictured by? Is that the right way to say it? It's not "illustrated by," because that implies non-photographic pictures. It's not "pictured by," is it? Yeah that's probably incorrect. Anyway, the pictures on the site were taken by Elizabeth Groeschen.
The goal of the project is to show the expat community--and the world at large, I suppose--that there is more to Seoul than the ubiquitous Hongdae-Downtown-Itaewon-Gangnam loop by writing a guide to the city--one subway stop at a time. As the sidebar on the homepage points out, the Seoul Metro has over 400 stops, and most of those remain neighborhoods commuters hurtle under or over on their way to places of greater import. A visitor's guide it's not, but it is probably the most useful and well-documented guide to the city for people that actually live here that I've yet seen.
While some of the posts seem to be a little down in the mouth for a guidebook-esque blog--"To give you an accurate idea of what there is to see and do around Gubanpo Station, suffice to say that I knocked this post out on my lunch break"--overall the pair have shed light on some parts of Seoul that the average expat hasn't seen, like Ichon-dong's "Little Tokyo" or the antique market at Dapshimni station.
Beyond the more "famous" attractions and districts, there is virtually no easily accessible English language information on the remaining parts of this city of 12 million people. I wish these cats the best of luck with their project and recommend the posts to anyone living or planning to live in 서울.
Here's a link to a write-up from the Korea Herald.