There are a number of observatories to choose from, both in Seoul and in other regions. The 63 City not only offers a great view, but is home to an aquarium, an IMAX movie theater, an art gallery and a wax museum. The N Seoul Tower is located on top of Namsan Mountain (남산) right in the heart of downtown, and features a western-style revolving restaurant. If you are making a trip to the DMZ, the Eulji Observatory (을지전망대) and Dorasan Observatory (도라산전망대) let you see North Korea soldiers on guard and on clear days you can get a view of nearby mountains. Another good place to visit is the Odusan Unification Observatory (오두산통일전망대), which will give you a great understanding of the stark differences between North and Seoul Korea. Watch the sunrise at the Dokdo Observatory cable car and get a birds-eye-view of Ulleungdo Island (울릉도) on a clear day, the controversial Dokdo Island (독도).