Vacations

I'm figuring on travelling to Detroit and Cleveland this summer to take in ball games.  I know, why would somebody plan vacations to two of America's fastest dying cities.  I guess I just don't like crowds.  I figure I can go on the River Rouge factory tour while in Detroit, and maybe visit the Great Lakes Brewery in Cleveland.  Does anybody else have any recommendations for things to do in these fine Midwestern metropolii?  Here's a Cleveland tourism video.