Wisconsin is known for its natural beauty and has a large number of state parks to visit.
Greyhound busses provide travel throughout the state, along all major cities and towns along I-43, I-45, I-90, I-94, and more, servicing among others Appleton, Brookfield, Eau Claire, Fond du lac, Green Bay, Kenosha, La Crosse, Milwaukee, Oshkosh, Racine, Steven's Point, Waukesha, Wisconsin Dells, and more.
Milwaukee has one international airport (General Mitchel). Madison and Oshkosh both have regional hubs (Dane County and Wittman Regional Airports, respectively).
There is a fast Amtrack Metro line that travels between Milwaukee and Chicago, stopping at Kenosha and Racine. There is also a regular passenger Amtrak line that effectively parallels I-94.
Noah's Ark is "America's largest Waterpark" in Wisconsin Dells. Wisconsin Dells is full of waterparks, amusement parks, shopping and shows. It also includes Tommy Bartlett's Watershow, one of the world's greatest waterski shows. Wisconsin Dells is also famous for its ducks, truck-like vehicles that can travel on land and sea that travel from lake to lake and along the rivers of "the Dells" to demonstrate the sights and nature.
Sheboygan is the home of the bratwurst and the hamburger, both of which having been invented there. The Bratwurst is a state delicacy served during summer cookouts, preferally boiled in beer prior to being grilled.
The hamburger was said to have been first served as a meatball-like product when its creator realized they stayed on the bun better if flattened. It was first sold at a Sheboygan fair. I cannot remember the name of the fair or the inventor - but I figure someone from Sheboygan could tell you.
Frozen custard is also a Wisconsin delicacy not found often outside the midwest. Frozen custard is similar to ice cream (it is NOT yogurt!). It is unique in that there is far less air in it (making it less "fluffy" and far more smooth and creamy). It contains egg, making it richer and creamier. It has an inappropriate reputation as unhealthy relative to ice cream when in fact most frozen custards have less calories, less fat and less sugar, being "less healthy" only in that it has slightly more cholesterol than ice cream.