I thought Bukhansan seen from Cheongdam Seongsu or Jamsil was really nice, but
Bukhansan seen from Yeouido is also really nice.
The buildings in Yongsan, Yeouido, and Mapo are prettier.
Look at how tall the buildings in Seongsu-dong are, blocking Bukhansan.
There is a height restriction in Yeouido/Mapo/Yongsan so that you can see Namsan Tower and Bukhansan a little.