Note: the museum is tiny, tiny, tiny.... You can see the whole place in less than an hour, easily, but it's definitely worth the trek to the northside.
This is a modern art museum, which definitely takes an interesting take on what modern art is (I guess modern art is always undefined, anyways). The top floor holds the temporary exhibits, so it's nice to start there and work your way down. When I was there a couple months ago they had some massive wood sculptures carved from tree trunks and one big installation which was basically a big hole that overlooked the neighbor's backyard. Very interesting.
My absolute favorite thing is the light exhibits on the 2nd floor. Take your beau and grab on. It's terrifying and fun at the same time. The one exhibit takes about 15-20 to show-up, but definitely wait it out. It's worth it. Don't forget that there are 2 other buildings outside with more to see that only take a minute or two to see.
FYI - there's no good way to get there via public transport, so hopefully you have a car.