The Guardian and the Fisher buildings are two of the most striking architecture masterpieces in Detroit. Both of them can be visited, either on your own or with a tour. Most of the city tours will take you through them. I would suggest joining the free architecture tour from the Detroit experience factory. http://detroitexperiencefactory.org/tours/ A little history and background never hurts. Indeed, you will want to know more about the cathedral-like hall of the Guardian as well as the gigantic chandeliers of the Fisher Building !
But if you do not have a lot of time on your hands, simply grab a coffee in the Guardian. It will be enough to understand how magnificent Detroit used to be.
The Guardian Buiding : 500 Griswold St, Detroit, MI 48226
Fisher Building : Fisher Bldg, 3011 W Grand Blvd, Detroit, MI 48202
Visit Detroit / Tourist in Detroit / Discover Detroit / Love Detroit