Ask a resident what the most unique structures in town are and they'll likely mention Immigration Tower. It's one of the first things that'll catch your eye when you start exploring.
You're spoiled for sightseeing choice when visiting Wan Chai. Immigration Tower is an ideal place to begin here, but there are loads of other interesting sights to appreciate. Ocean Park, Lan Kwai Fong, and Harbour City are close to the modern piece of architecture and will top off your day nicely.