Seoullo 7017 was built as an arboretum like link-bridge for locals and visitors to find a garden among one of the busiest part of Seoul -the Seoul station.
In the 1970s, an elevated road was built to connect the eastern and western sides around Seoul Station. However, the road was closed to road traffic due to safety issues. After this, rather than tearing down the existing structure, the road was transformed into Seoullo 7017, a new pedestrian walking experience Seoullo 7017 gets its name from its years of new life, from being a traffic road in the 70s to a sky garden in 2017. The "17" also has a deeper meaning, with Seoullo 7017 being divided into 17 unique sections, and the road being located 17 meters above the ground.
(* Credit: Visit Korea website: http://english.visitkorea.or.kr/enu/ATR/SI_EN_3_1_1_1.jsp?cid=2497803)
To fulfill its function of bridging people, you will find numerous installations at the bridge. One of which is the installation of pianos, presumably old pianos which had been painted and given a new lease of life. You can find visitors playing together along one of these pianos, and some looks like they had specially made an appointment to discuss music over the bridge. Regardless of each story, it serves its function well. There were about 5 or 6 of these pianos. and how are they maintained? you may ask. apparently, there will always be a "ranger" in uniform who is task to look after the bridge and that includes assets such as these pianos. How they can do oversee so many pianos on this long stretch is beyond me. But if it is in Seoul, I am sure they have an effective system that works.
Seoullo is touted to have other fixtures and activities, which unfortunately seemed to be non-operational on weekdays. But given the crowd, it may just not be viable to incur that kind of labour cost. Here's the seoullo official site, which has some information on the "must see sights". I did see some of them, such as the trampoline area and the basin to soak tired feet-- except that the basin has no water and I would have no way to know how it was suppose to be used. I would recommend making a reservation for a free night walk along seoullo.
I took the night tour, which starts from point A (See map below) to Namsan Park.
If you would like to check out Seoullo on your own, then there are numerous stairs and elevators where you can use. I would recommend points B, C, or D. Point C's elevator is just besides the Seoul station museum, which is actually the old Seoul station.
Point D starts from Namdaemun, or exit 5 at Hoehyeon station, and is another convenient location to access Seoullo.