Kobe City Hall's 24th-floor observation lobby is one of the easiest free viewpoints in the city. From the building on Flower Road you can look south across Port Island and the bay, north toward the Rokko range, and across the compact downtown around Sannomiya.
It is not a destination to build a whole day around, but it is a very practical first stop. Go early in your visit to understand Kobe's geography: mountains pressed close behind the city, harbour infrastructure in front, and a narrow urban strip running between them.