I've been here several times because my out-of-town guests almost always want to visit. The Olbrich Botanical Gardens is another one of those great, free gems in Madison! The outside is really picturesque, particularly the Thai Pavilion and Garden (which is my favorite). It is a decent size and they even have an indoor space (Bolz Conservatory), which is free from 10 AM to noon on Saturdays and Wednesdays ($2 the rest of the time)--something I've found to be a great escape from the Madison winter! I would also highly recommend visiting Bolz Conservatory during the Blooming Butterflies! Really neat to see all the butterflies. If you haven't visited Olbrich yet, you should!