Minneapolis is twenty minutes away by car or Blue Line light rail — the Mall of America station connects directly to downtown Minneapolis, so you can spend the morning at the mall and the afternoon in the city. St. Paul, Minnesota's capital and the quieter half of the Twin Cities, is about thirty minutes by car and well worth a half-day for Summit Avenue's Victorian mansion row and the magnificent Cass Gilbert state capitol. Both cities share an extensive light rail and bus network that makes combining them straightforward.
Historic Fort Snelling sits at the confluence of the Minnesota and Mississippi rivers, just north of Bloomington. The Minnesota Historical Society operates the restored 19th-century fort as a living history site, and the surrounding state park offers good riverside hiking and birdwatching — a full half-day from Bloomington.