The Seoul Station overpass was constructed in 1970 as a response to the growing traffic congestion in Seoul. For decades, the highway connected the eastern and western halves of the city. Once an elevated highway, it has been transformed into Seoullo 7017, an elevated public park for pedestrians. Seoullo 7017’s name is a nod to its origins; 70 for the year the overpass was first constructed, and 17 for the year of the highway’s rebirth. The number 17 also refers to the number of pedestrian paths that make up Seoullo. Where cars once sped along, people will now be able to wander. Visit the footpaths of Seoullo and experience Seoul’s history and culture while having fun!

http://english.visitseoul.net/tours/All-about-Seoullo-7017_/21502