Seoul. With a metro population of more than 25 million, Seoul is a lively, economic powerhouse. Home to several of the world’s largest companies (Samsung Electronics, LG, Kia, and Hyundai Motors, to name a few), this city truly never sleeps. If you love spicy food, then you’re in the right place! Korean BBQ is the city’s favorite food. Seoul’s nightlife is almost non-stop and a trip to Gangnam or Hongdae is open until the early hours.