Mix picturesque Italian architecture with modern art exhibits and you'll find Milwaukee's most underrated gallery. Villa Terrace is part museum, part marvel, all gorgeous. Go after hours and climb the fence to walk the gardens on your own private tour or stop in during a quiet time to walk the halls, peruse the art, and escape onto the rooftop. As long as no one's looking, there are also closed-off rooms and balconies perfect for a little sneaky exploration, as long as you're okay with jiggling a few door handles.
If you're coming at a time when the museum is closed, walk around to the left side and climb down the side of the stone wall. It shouldn't be that difficult... if you're having trouble, you're doing it wrong. From here you should have access to the lower garage, outdoor terrace, and gardens. If you're good at climbing, you can probably get to the roof as well (and therefore, the inner terrace). Leave the way you came or hop the fence at any point.
Have you been to this site? What did you think? Leave any tips of your own or observations in the comments to help other explorers!