Minneapolis has a lot to offer retirees -- art museums, professional sports teams, walkable neighborhoods and an international airport -- but if there's one thing that defines this city, it's water. There are 22 lakes within city limits, not to mention the mighty Mississippi River.

The Grand Rounds National Scenic Byway makes it easy to explore all of this shoreline by bike, foot or -- as is often the case in the winter -- ski. No doubt, winters here get darn cold (January lows are in the single digits), but this city embraces it with ice-carving competitions, sled rallies and polar plunges.