When Marvel announced that Black Panther would film in Busan,the moment largest city in South Korea, it was a grand deal. Seoul tends to get all the major movie contracts like Star Trek Beyond, or The Bourne Legacy,and Colossal. Marvel had already dipped its toes into the South Korean capital with 2014's Avengers: Age of Ultron, which shot in several locations in Seoul.
Source: blastr.com