If you go to Lotte Welfare Centre from the Sinsa station of #3 Seoul Metro, you should come through the tunnel for person.
Upside of the tunnel is KyeongBu Express Way..
The container of the cache is small size and white color...
You can use ball point pen for logging, but I suggest for you to use a Name Pen (Oil-Based Pen), because the log sheet of Cache is made with plastic.
After logging, please carefully lay on original location and covered with small stone...