Lotte World Tower is a 123-floor 555.7-metre skyscraper located in Seoul, South Korea. It opened to the public on April 11, 2017 and is currently the tallest building in South Korea, and is the 6th tallest building in the world.
Wikipedia https://en.wikipedia.org/wiki/Lotte_World_Tower
Coordinates 37°30'45.66" N 127°6'9.401" E