The Royal Norwegian Embassy is located on the 13th floor in the Jeongdong-building. The easiest way to get to the embassy is to take metro line nr. 2 (dark green line) to City Hall. After that, exit the metro through exit 12 and turn northwest, walking alongside the Deoksugung on the southern side. When you reach the street Jeongdong-gil, follow it for roughly 500 meters, and you should see a sign to your right pointing you to the location of the embassy.
13th fl. Jeong-dong Building