For California Seoul, head to Koreatown, where Art Deco buildings, palm trees, and low-rise strip malls line a grid of streets roughly one-third the size of Santa Monica. In place of sunny awnings, signs in Korean – sometimes with English translations – mark the fronts of bakeries, beauty salons, bubble tea shops, clothing boutiques and Korean BBQ restaurants. There’s a significant Latino culinary influence here as well, which extends from the traditional taqueria to the Korean taco truck. Formed in the 1970s and ’80s by Asian immigrants, Koreatown is not only home to the largest Korean population...