Everland is the biggest theme park in Korea. It is pretty cold to visit Everland in winter time cause it is outdoor park but you should visit anyway cause they are performing fireworks every day! For December whole month, they are showing parade and fireworks every night. Even you don’t like theme park, fireworks and parade is worth to watch. It is located outskirts of Seoul but we have good public transportation like subway and buses going to Everland.
Before fireworks, you can enjoy Christmas themes around the park. It is big part so it will take a lot of time even without rides.
Personally I don’t like thrill rides but I always visit Everland to go to the Safari. You can enjoy safari by big safari bus or private SUV tour. You can enjoy wild lives in hand touch distance. So if you like animals, this place is worth to visit. So please check operation hours and visit Safari also.