Signage is normally in Hangul and Romanized. Most coastal towns seem to have their fresh-off-the-boat seafood restaurants, with categories of cooked, raw, and still wriggling. In Sokcho, there are a number of raw-fish restaurants (hwet-jibs) along the beach. In Pusan we once went to a nearby village and had fish stews along the waterfront, and we did the same thing in Cheju as well. The beach areas are very quiet in the winter. These places all have aquaria for the various species, and you can get things like live octopus, raw crab in pepper sauce, and various types of braised or grilled fish. I seem to remember having a lot of this stuff in Seoul. You could cover a lot of ground there, and then pick a few areas for further research. Seoul also has things like North Korean noodles that you can't get anywhere else. Even the rest stops on the highway seem to have some good stuff, mixed with mediocre packaged food that's supposed to be "modern". Out in the parking lots they'll have guys grilling octopus on hot stones, while the tourists go in for their styrofoam ramyon. Temple food is interesting too. There's a place in Insadong that has Buddhist food - no garlic, vegetarian, etc. Temples usually have food available under some circumstances, although I've usually eaten in conjunction with some private event. My wife swears by the grilled-meat-and-soju stalls on the sidewalks. These are often open late. Also, the coffee has gotten a lot better in the last few years. The cafes have Italian Espresso.