Korean cuisine can be found in North Korea, South Korea and Northeast China as well as with the Korean diaspora around the world.
Korean cuisine often is based on rice and noodles in common with Chinese cuisine and Japanese cuisine, although indigenous ingredients such as fermented spicy cabbage (kimchi — 김치), rice cakes (떡 'duk') and various fermented bean sauces produce many dishes quite distinct from typical Japanese and Chinese cuisine.
Regional variations and specialities inside Korea do certainly exist, although typically 'the basics' can be found everywhere.
Many may consider Korean marinated barbecue meat of beef, pork and chicken to be the canonical Korean food. In fact, visits to these restaurants are typically reserved for special occasions. You typically visit in a large group and order large amounts of raw meat which you cut yourself with large scissors and cook yourself on a gas (or charcoal) cookers in the middle of the table. When cooked, the meat should be dipped in chilli sauce and wrapped in lettuce or perilla leaves. A high strength air vent is positioned above the cooker to avoid too much smoke landing on you.
A good amount of food in South Korea has also been inspired by American cuisine such as spicy twice-fried chicken (양념 치킨), which is actually more crispy and has less oil than its American counterpart. It is served generally with either plain or with a very sticky sweet marinade (or combination of both).
Soondae (순대) is a black sausage made from blood and glass noodles and wrapped in intestines (and very much not the western ice-cream dessert with the same spelling). Very much lacking in any flavor by itself, but combined with chilli makes for a delicious experience. Available by itself with chilli-salt, or in hot pots. Sokcho has a variety made completely from squid.
Koreans often snack on kimbap (김밥, the name is a portmanteau of "seaweed" and "rice") which looks like large pieces of Japanese sushi but is usually filled with pickled vegetables, fish cake, sesame oil and sometimes cooked meat. It is always wrapped in dry seaweed.
Korea has many dog and whale meat restaurants. These are almost never targeted at foreigners, so you will have to ask your local contacts to take you if you so wish. The legal status of these restaurants is ambiguous, although you are not likely to get into trouble by visiting one. The provenance of the meat will certainly not be that of high welfare, and high levels of toxins in whale (and dolphin) meat can be considered dangerous to consume.
Soju (소주) is a clear, distilled beverage made from rice, wheat or barley (or sometimes sweet potato or other root vegetables) that is the most popular alcoholic drink in Korea. Has some similarities to vodka but is not as strong and has a touch of sweetness.
Tea (차) is widely drunk, as elsewhere in East Asia. There's a range of Korean teas, for example
The following destinations may be of interest for authentic regional dishes. Many of these are also available in some form in specialized restaurants in South Korean cities (and to a somewhat lesser extent Korean restaurants around the world).
Naengmyeon (S) / Raengmyeon (N) (냉면 / 랭면). This ice cold noodle dish originates in the North Korean cities of Pyongyang 📍 and Hamhung 📍, with each city having its own distinctive style. A famous restaurant called Okryugwan (옥류관) in the North Korean capital is one place there that serves this. In South Korea, the city of Jinju 📍 also has a famous version (and somewhat easier to visit). In China, a famous variant of the dish is made by the ethnic Korean community in Yanji 📍. 2018-10-30
Squid Sundae (오징어 순대), 38.206°, 128.59°. A local variation of squid sausage is found in Sokcho, along with an annual Squid Festival. 2018-10-30
Hwangnam-ppang (황남빵, 경주빵), 35.8500°, 129.2167°. Famous pastry from Gyeongju, baked and filled with a slightly sweet red bean paste. It is customary to visit the historical sights of the city, and then buy a box of these on the way home. 2018-10-30
Jagalchi Fish Market (자갈치시장), 35.096°, 129.03°. Busan is South Korea's main seaport, and that is reflected in the large amount of seafood traded here. You can easily spend a day here both looking through the market and then eating at the many restaurants around it. The market opens very early in the morning, so a spicy dish at 5AM in the morning can be the perfect end to a hard night out. 2018-10-30
Gijang Crab Market (부산 기장시장), 35.265256°, 129.2059°. Somewhat off the beaten track outside Busan, this is nevertheless a top regional destination for crab specialities. Large and small crabs, cooked and raw (marinated in soy sauce) available. 2018-10-31
Honghap Jjim - Mussel stew (홍합찜), 37.5000°, 130.8667°. It takes a while to get to the island of Ulleungdo, east of the Korean mainland, but there are many unique Korean foods to be found here including this spicy mussel stew. 2018-10-31
Uijeongbu. Known for budae jjigae, literally "military unit stew", a dish made of sausage, spam, instant noodles, kimchi and other ingredients. The dish traces its origin to the U.S. military presence in South Korea during the Korean War, when the then-impoverished Koreans put together a dish from the scraps that were thrown out by the American soldiers, but also combining them with some cheap and widely-available traditional Korean ingredients. 2023-01-04