Nice attraction. Visit day and night to get two differing views of the city and the star. Zoo is nearby as well as several hiking trails.
Great spot downtown. The slices are huge.
Nice zoo to take younger children. Good way to spend a couple of hours.
Not actually in Roanoke, but just up the road is the James River. Great for kayaking and fishing. Several places to put in and get out, so you can plan how long you want to be on the water. Check the water level on Twin Rivers Outfitters website.