When we visited Belfast it was gloriously sunny and sitting in the Botanical Gardens was an almost perfect way to spend the afternoon (apart from the almost criminal lack of ice cream).
The Botanical Gardens were really close to the University and it must be nice for the students to hang out there in the summer. However, there really isn’t much to see. It’s quite small and, as I said, there wasn’t any ice cream. But just around the corner is the Belfast Museum which is quite nice.