The downtown skyway system is unique to Minneapolis, St. Paul and Duluth. Because of the weather in the winter these cities developed a way to connect to other buildings on the second floor via skyways that cross the streets. Over the years, the system expanded to the extent that most people use the skyways to go from building to building and this has resulted in sort of a second story mall experience, meaning most of the commerce during inclement weather is on the skyway. Although it is most vibrant during the day, it is an attraction to these cities because there are a lot of stores, resturants etc. that are interesting. Folks from out of town are often amazed by the system, we are used to it but it is pretty cool if you haven't seen it. You can walk for miles in any of these cities downtown via skyway.