In summer, there is simply no comparison to any other spot on earth, much less out the backdoor of any student union at a college or university in the country.
The Union Terrace is clean, relaxing, full of people, with great staff that keeps the food coming, brats on the grill, beer selection flowing, and live music and movies all in full view of Lake Mendota, sailboats, windsurfing.
I was there this past week and found myself relaxing for hours -- for the first time in a long while! Great for the students and visitors too!