he mountain is called Yongdusan ( yong : dragon, du: head and san : mountain)
because it seems like a dragon head.
It was also called Choryang Sosan, Songhyeonsan or Junsan .
In the past,
there was a shrine wishing for safe seaways and prosperous commerce in Yongdusan. In 1930s, its status was elevated to a National shrine .
it was named Unam park after the pen name of. Dr.Syngman Rhee,
the first president of korea.
In 1973, the present Busan Tower was constructed .
detail reference http://blog.daum.net/damotoli/7281326