The buildings of Minneapolis are connected by 10 miles of skyways on the second level. If it’s raining, snowing or 0 degrees (which happens in the winter) - you don't have to go outside! Many buildings close their skyway after 6pm, but during the day they can make for great exploration. Some notable spots are Cardigan Donuts in the IDS building, the downtown Target store, Brothers Deli, and Wave Sushi. The Royal Sonesta and Dakota Jazz Club are both accessible via skyway - see website for map or ask a Minnesota-nice local in the skyway.
The Mississippi River begins in Minnesota! The address listed will take you to the Stone Arch Bridge, a great pedestrian and tourist spot where you can see the St. Anthony Waterfalls and dam. There are many other options to view the river, including nearby Hennepin Ave Bridge and Boom Island Park. Both Our Lady of Lourdes Church (Saturday) and Elsie’s (Friday) are along the banks of the Mississippi River.
Minnesota is home to 10,000+ lakes. Some options with food and sights include Bde Maka Ska and Lake Harriet. This particular one, Lake of the Isles, is a favorite. If you'd like to join the long-standing ultimate frisbee game on Wednesday evening next to the lake, contact the bride.
Trek to the Saint Paul side: Visit the monkeys and polar bears and check out the plants in the lovely indoor conservatory. Smaller zoo, and manageable for families with little ones. Gardens here are very zen, and a favorite of the groom & bride. Free.